diff --git a/serde_codegen/Cargo.toml b/serde_codegen/Cargo.toml
index 703575e7..9fa605c4 100644
--- a/serde_codegen/Cargo.toml
+++ b/serde_codegen/Cargo.toml
@@ -8,31 +8,23 @@ homepage = "https://serde.rs"
 repository = "https://github.com/serde-rs/serde"
 documentation = "https://serde.rs/codegen.html"
 keywords = ["serde", "serialization"]
-build = "build.rs"
-include = ["Cargo.toml", "build.rs", "src/**/*.rs", "src/lib.rs.in"]
+include = ["Cargo.toml", "src/**/*.rs"]
 
 [features]
 default = ["with-syntex"]
-unstable = ["quasi_macros"]
+unstable = []
 unstable-testing = ["clippy"]
 with-syntex = [
-    "quasi/with-syntex",
-    "quasi_codegen",
-    "quasi_codegen/with-syntex",
-    "serde_codegen_internals/with-syntex",
     "syntex",
     "syntex_syntax",
 ]
-
-[build-dependencies]
-quasi_codegen = { version = "^0.19.0", optional = true }
-syntex = { version = "^0.43.0", optional = true }
+with-libsyntax = []
+with-syn = []
 
 [dependencies]
-aster = { version = "^0.26.0", default-features = false }
 clippy = { version = "^0.*", optional = true }
-quasi = { version = "^0.19.0", default-features = false }
-quasi_macros = { version = "^0.19.0", optional = true }
+quote = "0.1"
 serde_codegen_internals = { version = "=0.8.0", default-features = false, path = "../serde_codegen_internals" }
+syn = { version = "0.5", features = ["aster", "visit"] }
 syntex = { version = "^0.43.0", optional = true }
 syntex_syntax = { version = "^0.43.0", optional = true }
diff --git a/serde_codegen/build.rs b/serde_codegen/build.rs
deleted file mode 100644
index 9ff828f2..00000000
--- a/serde_codegen/build.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-#[cfg(feature = "with-syntex")]
-mod inner {
-    extern crate quasi_codegen;
-
-    use std::env;
-    use std::path::Path;
-    use std::thread::spawn;
-
-    pub fn main() {
-        // put everything into a thread, so users can use `RUST_MIN_STACK` to increase the amount of stack
-        spawn(|| {
-            let out_dir = env::var_os("OUT_DIR").unwrap();
-
-            let src = Path::new("src/lib.rs.in");
-            let dst = Path::new(&out_dir).join("lib.rs");
-            quasi_codegen::expand(&src, &dst).unwrap();
-        }).join().unwrap()
-    }
-}
-
-#[cfg(not(feature = "with-syntex"))]
-mod inner {
-    pub fn main() {}
-}
-
-fn main() {
-    inner::main();
-}
diff --git a/serde_codegen/src/bound.rs b/serde_codegen/src/bound.rs
index 7bd5ddc6..fef77ba3 100644
--- a/serde_codegen/src/bound.rs
+++ b/serde_codegen/src/bound.rs
@@ -1,9 +1,6 @@
 use std::collections::HashSet;
 
-use aster::AstBuilder;
-
-use syntax::ast;
-use syntax::visit;
+use syn::{self, aster, visit};
 
 use internals::ast::Item;
 use internals::attr;
@@ -11,10 +8,10 @@ use internals::attr;
 // Remove the default from every type parameter because in the generated impls
 // they look like associated types: "error: associated type bindings are not
 // allowed here".
-pub fn without_defaults(generics: &ast::Generics) -> ast::Generics {
-    ast::Generics {
+pub fn without_defaults(generics: &syn::Generics) -> syn::Generics {
+    syn::Generics {
         ty_params: generics.ty_params.iter().map(|ty_param| {
-            ast::TyParam {
+            syn::TyParam {
                 default: None,
                 .. ty_param.clone()
             }}).collect(),
@@ -23,24 +20,22 @@ pub fn without_defaults(generics: &ast::Generics) -> ast::Generics {
 }
 
 pub fn with_where_predicates(
-    builder: &AstBuilder,
-    generics: &ast::Generics,
-    predicates: &[ast::WherePredicate],
-) -> ast::Generics {
-    builder.from_generics(generics.clone())
+    generics: &syn::Generics,
+    predicates: &[syn::WherePredicate],
+) -> syn::Generics {
+    aster::from_generics(generics.clone())
         .with_predicates(predicates.to_vec())
         .build()
 }
 
 pub fn with_where_predicates_from_fields<F>(
-    builder: &AstBuilder,
     item: &Item,
-    generics: &ast::Generics,
+    generics: &syn::Generics,
     from_field: F,
-) -> ast::Generics
-    where F: Fn(&attr::Field) -> Option<&[ast::WherePredicate]>,
+) -> syn::Generics
+    where F: Fn(&attr::Field) -> Option<&[syn::WherePredicate]>,
 {
-    builder.from_generics(generics.clone())
+    aster::from_generics(generics.clone())
         .with_predicates(
             item.body.all_fields()
                 .flat_map(|field| from_field(&field.attrs))
@@ -60,34 +55,33 @@ pub fn with_where_predicates_from_fields<F>(
 //         c: C,
 //     }
 pub fn with_bound<F>(
-    builder: &AstBuilder,
     item: &Item,
-    generics: &ast::Generics,
+    generics: &syn::Generics,
     filter: F,
-    bound: &ast::Path,
-) -> ast::Generics
+    bound: &syn::Path,
+) -> syn::Generics
     where F: Fn(&attr::Field) -> bool,
 {
     struct FindTyParams {
         // Set of all generic type parameters on the current struct (A, B, C in
         // the example). Initialized up front.
-        all_ty_params: HashSet<ast::Name>,
+        all_ty_params: HashSet<syn::Ident>,
         // Set of generic type parameters used in fields for which filter
         // returns true (A and B in the example). Filled in as the visitor sees
         // them.
-        relevant_ty_params: HashSet<ast::Name>,
+        relevant_ty_params: HashSet<syn::Ident>,
     }
     impl visit::Visitor for FindTyParams {
-        fn visit_path(&mut self, path: &ast::Path, _id: ast::NodeId) {
+        fn visit_path(&mut self, path: &syn::Path) {
             if let Some(seg) = path.segments.last() {
-                if seg.identifier.name.as_str() == "PhantomData" {
+                if seg.ident == "PhantomData" {
                     // Hardcoded exception, because PhantomData<T> implements
                     // Serialize and Deserialize whether or not T implements it.
                     return;
                 }
             }
             if !path.global && path.segments.len() == 1 {
-                let id = path.segments[0].identifier.name;
+                let id = path.segments[0].ident.clone();
                 if self.all_ty_params.contains(&id) {
                     self.relevant_ty_params.insert(id);
                 }
@@ -97,7 +91,7 @@ pub fn with_bound<F>(
     }
 
     let all_ty_params: HashSet<_> = generics.ty_params.iter()
-        .map(|ty_param| ty_param.ident.name)
+        .map(|ty_param| ty_param.ident.clone())
         .collect();
 
     let relevant_tys = item.body.all_fields()
@@ -112,14 +106,14 @@ pub fn with_bound<F>(
         visit::walk_ty(&mut visitor, ty);
     }
 
-    builder.from_generics(generics.clone())
+    aster::from_generics(generics.clone())
         .with_predicates(
             generics.ty_params.iter()
-                .map(|ty_param| ty_param.ident.name)
+                .map(|ty_param| ty_param.ident.clone())
                 .filter(|id| visitor.relevant_ty_params.contains(id))
-                .map(|id| builder.where_predicate()
+                .map(|id| aster::where_predicate()
                     // the type parameter that is being bounded e.g. T
-                    .bound().build(builder.ty().id(id))
+                    .bound().build(aster::ty().id(id))
                     // the bound e.g. Serialize
                     .bound().trait_(bound.clone()).build()
                     .build()))
diff --git a/serde_codegen/src/lib.rs b/serde_codegen/src/lib.rs
index 55318af6..7de4db6d 100644
--- a/serde_codegen/src/lib.rs
+++ b/serde_codegen/src/lib.rs
@@ -2,11 +2,8 @@
 #![cfg_attr(feature = "clippy", feature(plugin))]
 #![cfg_attr(feature = "clippy", allow(too_many_arguments))]
 #![cfg_attr(feature = "clippy", allow(used_underscore_binding))]
-#![cfg_attr(not(feature = "with-syntex"), feature(rustc_private, plugin))]
-#![cfg_attr(not(feature = "with-syntex"), plugin(quasi_macros))]
+#![cfg_attr(feature = "with-libsyntax", feature(rustc_private, plugin))]
 
-extern crate aster;
-extern crate quasi;
 extern crate serde_codegen_internals as internals;
 
 #[cfg(feature = "with-syntex")]
@@ -16,24 +13,25 @@ extern crate syntex;
 #[macro_use]
 extern crate syntex_syntax as syntax;
 
-#[cfg(not(feature = "with-syntex"))]
+#[cfg(feature = "with-libsyntax")]
 #[macro_use]
 extern crate syntax;
 
-#[cfg(not(feature = "with-syntex"))]
+#[cfg(feature = "with-libsyntax")]
 extern crate rustc_plugin;
 
+extern crate syn;
+#[macro_use]
+extern crate quote;
+
 #[cfg(feature = "with-syntex")]
 use std::path::Path;
 
-#[cfg(not(feature = "with-syntex"))]
+#[cfg(feature = "with-libsyntax")]
 use syntax::feature_gate::AttributeType;
 
-#[cfg(feature = "with-syntex")]
-include!(concat!(env!("OUT_DIR"), "/lib.rs"));
-
-#[cfg(not(feature = "with-syntex"))]
-include!("lib.rs.in");
+mod bound;
+mod ser;
 
 #[cfg(feature = "with-syntex")]
 fn syntex_registry() -> syntex::Registry {
@@ -68,7 +66,7 @@ fn syntex_registry() -> syntex::Registry {
     reg.add_attr("feature(custom_derive)");
     reg.add_attr("feature(custom_attribute)");
 
-    reg.add_decorator("derive_Serialize", ser::expand_derive_serialize);
+    reg.add_decorator("derive_Serialize", expand_derive_serialize);
     reg.add_decorator("derive_Deserialize", de::expand_derive_deserialize);
 
     reg.add_post_expansion_pass(strip_attributes);
@@ -102,17 +100,168 @@ pub fn expand<S, D>(src: S, dst: D) -> Result<(), syntex::Error>
     syntex::with_extra_stack(expand_thread)
 }
 
-#[cfg(not(feature = "with-syntex"))]
+#[cfg(feature = "with-libsyntax")]
 pub fn register(reg: &mut rustc_plugin::Registry) {
     reg.register_syntax_extension(
         syntax::parse::token::intern("derive_Serialize"),
         syntax::ext::base::MultiDecorator(
-            Box::new(ser::expand_derive_serialize)));
+            Box::new(expand_derive_serialize)));
 
-    reg.register_syntax_extension(
+    /*reg.register_syntax_extension(
         syntax::parse::token::intern("derive_Deserialize"),
         syntax::ext::base::MultiDecorator(
-            Box::new(de::expand_derive_deserialize)));
+            Box::new(de::expand_derive_deserialize)));*/
 
     reg.register_attribute("serde".to_owned(), AttributeType::Normal);
 }
+
+#[cfg(any(feature = "with-syntex", feature = "with-libsyntax"))]
+use syntax::ast::MetaItem;
+#[cfg(any(feature = "with-syntex", feature = "with-libsyntax"))]
+use syntax::codemap::Span;
+#[cfg(any(feature = "with-syntex", feature = "with-libsyntax"))]
+use syntax::ext::base::{Annotatable, ExtCtxt};
+
+#[cfg(any(feature = "with-syntex", feature = "with-libsyntax"))]
+fn expand_derive_serialize(
+    cx: &mut ExtCtxt,
+    _span: Span,
+    meta_item: &MetaItem,
+    annotatable: &Annotatable,
+    push: &mut FnMut(Annotatable)
+) {
+    let item = match *annotatable {
+        Annotatable::Item(ref item) => item,
+        _ => {
+            cx.span_err(
+                meta_item.span,
+                "`#[derive(Serialize)]` may only be applied to structs and enums");
+            return;
+        }
+    };
+
+    use syntax::print::pprust;
+    let s = pprust::item_to_string(item);
+
+    let syn_item = syn::parse_item(&s).unwrap();
+    let expanded = ser::expand_derive_serialize(&syn_item).to_string();
+
+    use syntax::parse;
+    let name = "Serialize".to_string();
+    let cfg = Vec::new();
+    let sess = parse::ParseSess::new();
+    let impl_item = parse::parse_item_from_source_str(name, expanded, cfg, &sess);
+    push(Annotatable::Item(impl_item.unwrap().unwrap()));
+}
+
+#[cfg(feature = "with-syn")]
+pub fn expand_single_item(item: &str) -> String {
+    let syn_item = syn::parse_item(item).unwrap();
+    let (ser, de, syn_item) = strip_serde_derives(syn_item);
+    let expanded_ser = if ser {
+        Some(ser::expand_derive_serialize(&syn_item))
+    } else {
+        None
+    };
+    let expanded_de = if de {
+        unimplemented!()
+    } else {
+        None::<quote::Tokens>
+    };
+    let syn_item = strip_serde_attrs(syn_item);
+    return quote!(#expanded_ser #expanded_de #syn_item).to_string();
+
+    fn strip_serde_derives(item: syn::Item) -> (bool, bool, syn::Item) {
+        let mut ser = false;
+        let mut de = false;
+        let item = syn::Item {
+            attrs: item.attrs.into_iter().flat_map(|attr| {
+                if attr.is_sugared_doc {
+                    return Some(attr);
+                }
+                let (name, nested) = match attr.value {
+                    syn::MetaItem::List(name, nested) => (name, nested),
+                    _ => return Some(attr)
+                };
+                if name != "derive" {
+                    return Some(syn::Attribute {
+                        value: syn::MetaItem::List(name, nested),
+                        is_sugared_doc: false,
+                    });
+                }
+                let rest: Vec<_> = nested.into_iter().filter(|nested| {
+                    match *nested {
+                        syn::MetaItem::Word(ref word) if word == "Serialize" => {
+                            ser = true;
+                            false
+                        }
+                        syn::MetaItem::Word(ref word) if word == "Deserialize" => {
+                            de = true;
+                            false
+                        }
+                        _ => true,
+                    }
+                }).collect();
+                if rest.is_empty() {
+                    None
+                } else {
+                    Some(syn::Attribute {
+                        value: syn::MetaItem::List(name, rest),
+                        is_sugared_doc: false,
+                    })
+                }
+            }).collect(),
+            ..item
+        };
+        (ser, de, item)
+    }
+
+    fn strip_serde_attrs(item: syn::Item) -> syn::Item {
+        syn::Item {
+            attrs: strip_serde_from_attrs(item.attrs),
+            body: match item.body {
+                syn::Body::Enum(variants) => syn::Body::Enum(
+                    variants.into_iter().map(|variant| {
+                        syn::Variant {
+                            ident: variant.ident,
+                            attrs: strip_serde_from_attrs(variant.attrs),
+                            data: strip_serde_from_variant_data(variant.data),
+                        }
+                    }).collect()
+                ),
+                syn::Body::Struct(variant_data) => syn::Body::Struct(
+                    strip_serde_from_variant_data(variant_data)
+                ),
+            },
+            ..item
+        }
+    }
+
+    fn strip_serde_from_variant_data(data: syn::VariantData) -> syn::VariantData {
+        match data {
+            syn::VariantData::Struct(fields) => syn::VariantData::Struct(
+                fields.into_iter().map(strip_serde_from_field).collect()
+            ),
+            syn::VariantData::Tuple(fields) => syn::VariantData::Tuple(
+                fields.into_iter().map(strip_serde_from_field).collect()
+            ),
+            syn::VariantData::Unit => syn::VariantData::Unit,
+        }
+    }
+
+    fn strip_serde_from_field(field: syn::Field) -> syn::Field {
+        syn::Field {
+            attrs: strip_serde_from_attrs(field.attrs),
+            ..field
+        }
+    }
+
+    fn strip_serde_from_attrs(attrs: Vec<syn::Attribute>) -> Vec<syn::Attribute> {
+        attrs.into_iter().filter(|attr| {
+            match attr.value {
+                syn::MetaItem::List(ref ident, _) => ident != "serde",
+                _ => true,
+            }
+        }).collect()
+    }
+}
diff --git a/serde_codegen/src/lib.rs.in b/serde_codegen/src/lib.rs.in
deleted file mode 100644
index 08dd5d3c..00000000
--- a/serde_codegen/src/lib.rs.in
+++ /dev/null
@@ -1,4 +0,0 @@
-mod bound;
-mod de;
-mod ser;
-mod span;
diff --git a/serde_codegen/src/ser.rs b/serde_codegen/src/ser.rs
index d4883e8e..448c974c 100644
--- a/serde_codegen/src/ser.rs
+++ b/serde_codegen/src/ser.rs
@@ -1,103 +1,60 @@
-use aster;
-
-use syntax::ast::{self, Ident, MetaItem};
-use syntax::codemap::Span;
-use syntax::ext::base::{Annotatable, ExtCtxt};
-use syntax::ptr::P;
-use syntax::tokenstream::TokenTree;
+use syn::{self, aster};
+use quote::Tokens;
 
 use bound;
-use span;
 use internals::ast::{Body, Field, Item, Style, Variant};
-use internals::{attr, Error};
+use internals::{self, attr};
 
-pub fn expand_derive_serialize(
-    cx: &mut ExtCtxt,
-    span: Span,
-    meta_item: &MetaItem,
-    annotatable: &Annotatable,
-    push: &mut FnMut(Annotatable)
-) {
-    let item = match *annotatable {
-        Annotatable::Item(ref item) => item,
-        _ => {
-            cx.span_err(
-                meta_item.span,
-                "`#[derive(Serialize)]` may only be applied to structs and enums");
-            return;
-        }
-    };
+pub fn expand_derive_serialize(item: &syn::Item) -> Tokens {
+    let item = Item::from_ast(&internals::Ctxt::new(), item);
 
-    let item = match Item::from_ast(cx, item) {
-        Ok(item) => item,
-        Err(Error::UnexpectedItemKind) => {
-            cx.span_err(item.span,
-                "`#[derive(Serialize)]` may only be applied to structs and enums");
-            return;
-        }
-    };
+    let impl_generics = build_impl_generics(&item);
 
-    let builder = aster::AstBuilder::new().span(span);
-
-    let impl_item = serialize_item(cx, &builder, &item);
-    push(span::record_expansion(cx, impl_item, "Serialize"))
-}
-
-fn serialize_item(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    item: &Item,
-) -> P<ast::Item> {
-    let impl_generics = build_impl_generics(builder, &item);
-
-    let ty = builder.ty().path()
-        .segment(item.ident).with_generics(impl_generics.clone()).build()
+    let ty = aster::ty().path()
+        .segment(item.ident.clone()).with_generics(impl_generics.clone()).build()
         .build();
 
-    let body = serialize_body(cx,
-                              builder,
-                              &item,
+    let body = serialize_body(&item,
                               &impl_generics,
                               ty.clone());
 
     let where_clause = &impl_generics.where_clause;
 
-    let dummy_const = builder.id(format!("_IMPL_SERIALIZE_FOR_{}", item.ident));
+    let dummy_const = aster::id(format!("_IMPL_SERIALIZE_FOR_{}", item.ident));
 
-    quote_item!(cx,
+    quote! {
         #[allow(non_upper_case_globals, unused_attributes, unused_qualifications)]
-        const $dummy_const: () = {
+        const #dummy_const: () = {
             extern crate serde as _serde;
             #[automatically_derived]
-            impl $impl_generics _serde::ser::Serialize for $ty $where_clause {
+            impl #impl_generics _serde::ser::Serialize for #ty #where_clause {
                 fn serialize<__S>(&self, _serializer: &mut __S) -> ::std::result::Result<(), __S::Error>
                     where __S: _serde::ser::Serializer
-                $body
+                {
+                    #body
+                }
             }
         };
-    ).unwrap()
+    }
 }
 
 // All the generics in the input, plus a bound `T: Serialize` for each generic
 // field type that will be serialized by us.
-fn build_impl_generics(
-    builder: &aster::AstBuilder,
-    item: &Item,
-) -> ast::Generics {
+fn build_impl_generics(item: &Item) -> syn::Generics {
     let generics = bound::without_defaults(item.generics);
 
     let generics = bound::with_where_predicates_from_fields(
-        builder, item, &generics,
+        item, &generics,
         |attrs| attrs.ser_bound());
 
     match item.attrs.ser_bound() {
         Some(predicates) => {
-            bound::with_where_predicates(builder, &generics, predicates)
+            bound::with_where_predicates(&generics, predicates)
         }
         None => {
-            bound::with_bound(builder, item, &generics,
+            bound::with_bound(item, &generics,
                 needs_serialize_bound,
-                &builder.path().ids(&["_serde", "ser", "Serialize"]).build())
+                &aster::path().ids(&["_serde", "ser", "Serialize"]).build())
         }
     }
 }
@@ -113,18 +70,14 @@ fn needs_serialize_bound(attrs: &attr::Field) -> bool {
 }
 
 fn serialize_body(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
     item: &Item,
-    impl_generics: &ast::Generics,
-    ty: P<ast::Ty>,
-) -> P<ast::Block> {
+    impl_generics: &syn::Generics,
+    ty: syn::Ty,
+) -> Tokens {
     match item.body {
         Body::Enum(ref variants) => {
             serialize_item_enum(
-                cx,
-                builder,
-                item.ident,
+                &item.ident,
                 impl_generics,
                 ty,
                 variants,
@@ -132,12 +85,10 @@ fn serialize_body(
         }
         Body::Struct(Style::Struct, ref fields) => {
             if fields.iter().any(|field| field.ident.is_none()) {
-                cx.span_bug(item.span, "struct has unnamed fields")
+                panic!("struct has unnamed fields");
             }
 
             serialize_struct(
-                cx,
-                builder,
                 impl_generics,
                 ty,
                 fields,
@@ -145,12 +96,10 @@ fn serialize_body(
         }
         Body::Struct(Style::Tuple, ref fields) => {
             if fields.iter().any(|field| field.ident.is_some()) {
-                cx.span_bug(item.span, "tuple struct has named fields")
+                panic!("tuple struct has named fields");
             }
 
             serialize_tuple_struct(
-                cx,
-                builder,
                 impl_generics,
                 ty,
                 fields,
@@ -158,8 +107,6 @@ fn serialize_body(
         }
         Body::Struct(Style::Newtype, ref fields) => {
             serialize_newtype_struct(
-                cx,
-                builder,
                 impl_generics,
                 ty,
                 &fields[0],
@@ -167,136 +114,116 @@ fn serialize_body(
         }
         Body::Struct(Style::Unit, _) => {
             serialize_unit_struct(
-                cx,
-                builder,
                 &item.attrs)
         }
     }
 }
 
-fn serialize_unit_struct(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    item_attrs: &attr::Item,
-) -> P<ast::Block> {
-    let type_name = name_expr(builder, item_attrs.name());
+fn serialize_unit_struct(item_attrs: &attr::Item) -> Tokens {
+    let type_name = item_attrs.name().serialize_name();
 
-    quote_block!(cx, {
-        _serializer.serialize_unit_struct($type_name)
-    }).unwrap()
+    quote! {
+        _serializer.serialize_unit_struct(#type_name)
+    }
 }
 
 fn serialize_newtype_struct(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    impl_generics: &ast::Generics,
-    item_ty: P<ast::Ty>,
+    impl_generics: &syn::Generics,
+    item_ty: syn::Ty,
     field: &Field,
     item_attrs: &attr::Item,
-) -> P<ast::Block> {
-    let type_name = name_expr(builder, item_attrs.name());
+) -> Tokens {
+    let type_name = item_attrs.name().serialize_name();
 
-    let mut field_expr = quote_expr!(cx, &self.0);
+    let mut field_expr = quote!(&self.0);
     if let Some(path) = field.attrs.serialize_with() {
-        field_expr = wrap_serialize_with(cx, builder,
+        field_expr = wrap_serialize_with(
             &item_ty, impl_generics, &field.ty, path, field_expr);
     }
 
-    quote_block!(cx, {
-        _serializer.serialize_newtype_struct($type_name, $field_expr)
-    }).unwrap()
+    quote! {
+        _serializer.serialize_newtype_struct(#type_name, #field_expr)
+    }
 }
 
 fn serialize_tuple_struct(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    impl_generics: &ast::Generics,
-    ty: P<ast::Ty>,
+    impl_generics: &syn::Generics,
+    ty: syn::Ty,
     fields: &[Field],
     item_attrs: &attr::Item,
-) -> P<ast::Block> {
+) -> Tokens {
     let serialize_stmts = serialize_tuple_struct_visitor(
-        cx,
-        builder,
         ty.clone(),
         fields,
         impl_generics,
         false,
-        cx.ident_of("serialize_tuple_struct_elt"),
+        aster::id("serialize_tuple_struct_elt"),
     );
 
-    let type_name = name_expr(builder, item_attrs.name());
+    let type_name = item_attrs.name().serialize_name();
     let len = serialize_stmts.len();
-    let let_mut = mut_if(cx, len > 0);
+    let let_mut = mut_if(len > 0);
 
-    quote_block!(cx, {
-        let $let_mut state = try!(_serializer.serialize_tuple_struct($type_name, $len));
-        $serialize_stmts
+    quote! {
+        let #let_mut state = try!(_serializer.serialize_tuple_struct(#type_name, #len));
+        #(serialize_stmts)*
         _serializer.serialize_tuple_struct_end(state)
-    }).unwrap()
+    }
 }
 
 fn serialize_struct(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    impl_generics: &ast::Generics,
-    ty: P<ast::Ty>,
+    impl_generics: &syn::Generics,
+    ty: syn::Ty,
     fields: &[Field],
     item_attrs: &attr::Item,
-) -> P<ast::Block> {
+) -> Tokens {
     let serialize_fields = serialize_struct_visitor(
-        cx,
-        builder,
         ty.clone(),
         fields,
         impl_generics,
         false,
-        cx.ident_of("serialize_struct_elt"),
+        aster::id("serialize_struct_elt"),
     );
 
-    let type_name = name_expr(builder, item_attrs.name());
+    let type_name = item_attrs.name().serialize_name();
 
     let mut serialized_fields = fields.iter()
         .filter(|&field| !field.attrs.skip_serializing())
         .peekable();
 
-    let let_mut = mut_if(cx, serialized_fields.peek().is_some());
+    let let_mut = mut_if(serialized_fields.peek().is_some());
 
     let len = serialized_fields
         .map(|field| {
-            let ident = field.ident.expect("struct has unnamed fields");
-            let field_expr = quote_expr!(cx, &self.$ident);
+            let ident = field.ident.clone().expect("struct has unnamed fields");
+            let field_expr = quote!(&self.#ident);
 
             match field.attrs.skip_serializing_if() {
-                Some(path) => quote_expr!(cx, if $path($field_expr) { 0 } else { 1 }),
-                None => quote_expr!(cx, 1),
+                Some(path) => quote!(if #path(#field_expr) { 0 } else { 1 }),
+                None => quote!(1),
             }
          })
-        .fold(quote_expr!(cx, 0), |sum, expr| quote_expr!(cx, $sum + $expr));
+        .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
 
-    quote_block!(cx, {
-        let $let_mut state = try!(_serializer.serialize_struct($type_name, $len));
-        $serialize_fields
+    quote! {
+        let #let_mut state = try!(_serializer.serialize_struct(#type_name, #len));
+        #(serialize_fields)*
         _serializer.serialize_struct_end(state)
-    }).unwrap()
+    }
 }
 
 fn serialize_item_enum(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    type_ident: Ident,
-    impl_generics: &ast::Generics,
-    ty: P<ast::Ty>,
+    type_ident: &syn::Ident,
+    impl_generics: &syn::Generics,
+    ty: syn::Ty,
     variants: &[Variant],
     item_attrs: &attr::Item,
-) -> P<ast::Block> {
+) -> Tokens {
     let arms: Vec<_> =
         variants.iter()
             .enumerate()
             .map(|(variant_index, variant)| {
                 serialize_variant(
-                    cx,
-                    builder,
                     type_ident,
                     impl_generics,
                     ty.clone(),
@@ -307,44 +234,40 @@ fn serialize_item_enum(
             })
             .collect();
 
-    quote_block!(cx, {
+    quote! {
         match *self {
-            $arms
+            #(arms)*
         }
-    }).unwrap()
+    }
 }
 
 fn serialize_variant(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    type_ident: Ident,
-    generics: &ast::Generics,
-    ty: P<ast::Ty>,
+    type_ident: &syn::Ident,
+    generics: &syn::Generics,
+    ty: syn::Ty,
     variant: &Variant,
     variant_index: usize,
     item_attrs: &attr::Item,
-) -> ast::Arm {
-    let type_name = name_expr(builder, item_attrs.name());
+) -> Tokens {
+    let type_name = item_attrs.name().serialize_name();
 
-    let variant_ident = variant.ident;
-    let variant_name = name_expr(builder, variant.attrs.name());
+    let variant_ident = variant.ident.clone();
+    let variant_name = variant.attrs.name().serialize_name();
 
     match variant.style {
         Style::Unit => {
-            quote_arm!(cx,
-                $type_ident::$variant_ident =>
+            quote! {
+                #type_ident::#variant_ident =>
                     _serde::ser::Serializer::serialize_unit_variant(
                         _serializer,
-                        $type_name,
-                        $variant_index,
-                        $variant_name,
+                        #type_name,
+                        #variant_index,
+                        #variant_name,
                     ),
-            )
+            }
         },
         Style::Newtype => {
             let block = serialize_newtype_variant(
-                cx,
-                builder,
                 type_name,
                 variant_index,
                 variant_name,
@@ -353,26 +276,21 @@ fn serialize_variant(
                 &variant.fields[0],
             );
 
-            quote_arm!(cx,
-                $type_ident::$variant_ident(ref __simple_value) => $block
-            )
+            quote! {
+                #type_ident::#variant_ident(ref __simple_value) => #block,
+            }
         },
         Style::Tuple => {
-            let field_names: Vec<ast::Ident> = (0 .. variant.fields.len())
-                .map(|i| builder.id(format!("__field{}", i)))
+            let field_names: Vec<Tokens> = (0 .. variant.fields.len())
+                .map(|i| {
+                    let id = aster::id(format!("__field{}", i));
+                    quote!(ref #id)
+                })
                 .collect();
 
-            let pat = builder.pat().enum_()
-                .id(type_ident).id(variant_ident).build()
-                .with_pats(
-                    field_names.iter()
-                        .map(|field| builder.pat().ref_id(field))
-                )
-                .build();
+            let pat = quote!(#type_ident::#variant_ident(#(field_names),*));
 
             let block = serialize_tuple_variant(
-                cx,
-                builder,
                 type_name,
                 variant_index,
                 variant_name,
@@ -381,28 +299,21 @@ fn serialize_variant(
                 &variant.fields,
             );
 
-            quote_arm!(cx,
-                $pat => $block
-            )
+            quote! {
+                #pat => { #block }
+            }
         }
         Style::Struct => {
-            let mut pat = builder.pat().struct_().id(type_ident).id(variant_ident).build();
-            for field in &variant.fields {
-                let name = match field.ident {
-                    Some(name) => name,
-                    None => cx.span_bug(field.span, "struct variant has unnamed fields"),
+            let fields = variant.fields.iter().map(|field| {
+                let id = match field.ident {
+                    Some(ref name) => name.clone(),
+                    None => panic!("struct variant has unnamed fields"),
                 };
-                pat = pat.with_field_pat(ast::FieldPat {
-                    ident: name,
-                    pat: builder.pat().ref_id(name),
-                    is_shorthand: true,
-                });
-            }
-            let pat = pat.build();
+                quote!(ref #id)
+            });
+            let pat = quote!(#type_ident::#variant_ident { #(fields),* });
 
             let block = serialize_struct_variant(
-                cx,
-                builder,
                 variant_index,
                 variant_name,
                 generics,
@@ -411,250 +322,228 @@ fn serialize_variant(
                 item_attrs,
             );
 
-            quote_arm!(cx,
-                $pat => $block
-            )
+            quote! {
+                #pat => { #block }
+            }
         }
     }
 }
 
 fn serialize_newtype_variant(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    type_name: P<ast::Expr>,
+    type_name: String,
     variant_index: usize,
-    variant_name: P<ast::Expr>,
-    item_ty: P<ast::Ty>,
-    generics: &ast::Generics,
+    variant_name: String,
+    item_ty: syn::Ty,
+    generics: &syn::Generics,
     field: &Field,
-) -> P<ast::Block> {
-    let mut field_expr = quote_expr!(cx, __simple_value);
+) -> Tokens {
+    let mut field_expr = quote!(__simple_value);
     if let Some(path) = field.attrs.serialize_with() {
-        field_expr = wrap_serialize_with(cx, builder,
+        field_expr = wrap_serialize_with(
             &item_ty, generics, &field.ty, path, field_expr);
     }
 
-    quote_block!(cx, {
+    quote! {
         _serde::ser::Serializer::serialize_newtype_variant(
             _serializer,
-            $type_name,
-            $variant_index,
-            $variant_name,
-            $field_expr,
+            #type_name,
+            #variant_index,
+            #variant_name,
+            #field_expr,
         )
-    }).unwrap()
+    }
 }
 
 fn serialize_tuple_variant(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    type_name: P<ast::Expr>,
+    type_name: String,
     variant_index: usize,
-    variant_name: P<ast::Expr>,
-    generics: &ast::Generics,
-    structure_ty: P<ast::Ty>,
+    variant_name: String,
+    generics: &syn::Generics,
+    structure_ty: syn::Ty,
     fields: &[Field],
-) -> P<ast::Block> {
+) -> Tokens {
     let serialize_stmts = serialize_tuple_struct_visitor(
-        cx,
-        builder,
         structure_ty,
         fields,
         generics,
         true,
-        cx.ident_of("serialize_tuple_variant_elt"),
+        aster::id("serialize_tuple_variant_elt"),
     );
 
     let len = serialize_stmts.len();
-    let let_mut = mut_if(cx, len > 0);
+    let let_mut = mut_if(len > 0);
 
-    quote_block!(cx, {
-        let $let_mut state = try!(_serializer.serialize_tuple_variant($type_name, $variant_index, $variant_name, $len));
-        $serialize_stmts
+    quote! {
+        let #let_mut state = try!(_serializer.serialize_tuple_variant(#type_name, #variant_index, #variant_name, #len));
+        #(serialize_stmts)*
         _serializer.serialize_tuple_variant_end(state)
-    }).unwrap()
+    }
 }
 
 fn serialize_struct_variant(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
     variant_index: usize,
-    variant_name: P<ast::Expr>,
-    generics: &ast::Generics,
-    ty: P<ast::Ty>,
+    variant_name: String,
+    generics: &syn::Generics,
+    ty: syn::Ty,
     fields: &[Field],
     item_attrs: &attr::Item,
-) -> P<ast::Block> {
-
+) -> Tokens {
     let serialize_fields = serialize_struct_visitor(
-        cx,
-        builder,
         ty.clone(),
         fields,
         &generics,
         true,
-        cx.ident_of("serialize_struct_variant_elt"),
+        aster::id("serialize_struct_variant_elt"),
     );
 
-    let item_name = name_expr(builder, item_attrs.name());
+    let item_name = item_attrs.name().serialize_name();
 
     let mut serialized_fields = fields.iter()
         .filter(|&field| !field.attrs.skip_serializing())
         .peekable();
 
-    let let_mut = mut_if(cx, serialized_fields.peek().is_some());
+    let let_mut = mut_if(serialized_fields.peek().is_some());
 
     let len = serialized_fields
         .map(|field| {
-            let ident = field.ident.expect("struct has unnamed fields");
-            let field_expr = quote_expr!(cx, $ident);
+            let ident = field.ident.clone().expect("struct has unnamed fields");
 
             match field.attrs.skip_serializing_if() {
-                Some(path) => quote_expr!(cx, if $path($field_expr) { 0 } else { 1 }),
-                None => quote_expr!(cx, 1),
+                Some(path) => quote!(if #path(#ident) { 0 } else { 1 }),
+                None => quote!(1),
             }
          })
-        .fold(quote_expr!(cx, 0), |sum, expr| quote_expr!(cx, $sum + $expr));
+        .fold(quote!(0), |sum, expr| quote!(#sum + #expr));
 
-    quote_block!(cx, {
-        let $let_mut state = try!(_serializer.serialize_struct_variant(
-            $item_name,
-            $variant_index,
-            $variant_name,
-            $len,
+    quote! {
+        let #let_mut state = try!(_serializer.serialize_struct_variant(
+            #item_name,
+            #variant_index,
+            #variant_name,
+            #len,
         ));
-        $serialize_fields
+        #(serialize_fields)*
         _serializer.serialize_struct_variant_end(state)
-    }).unwrap()
+    }
 }
 
 fn serialize_tuple_struct_visitor(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    structure_ty: P<ast::Ty>,
+    structure_ty: syn::Ty,
     fields: &[Field],
-    generics: &ast::Generics,
+    generics: &syn::Generics,
     is_enum: bool,
-    func: ast::Ident,
-) -> Vec<ast::Stmt> {
+    func: syn::Ident,
+) -> Vec<Tokens> {
     fields.iter()
         .enumerate()
         .map(|(i, field)| {
             let mut field_expr = if is_enum {
-                builder.expr().path().id(format!("__field{}", i)).build()
+                let id = aster::id(format!("__field{}", i));
+                quote!(#id)
             } else {
-                builder.expr().ref_().tup_field(i).self_()
+                quote!(&self.#i)
             };
 
             let skip = field.attrs.skip_serializing_if()
-                .map(|path| quote_expr!(cx, $path($field_expr)));
+                .map(|path| quote!(#path(#field_expr)));
 
             if let Some(path) = field.attrs.serialize_with() {
-                field_expr = wrap_serialize_with(cx, builder,
+                field_expr = wrap_serialize_with(
                     &structure_ty, generics, &field.ty, path, field_expr);
             }
 
-            let ser = quote_expr!(cx,
-                try!(_serializer.$func(&mut state, $field_expr));
-            );
+            let ser = quote! {
+                try!(_serializer.#func(&mut state, #field_expr));
+            };
 
             match skip {
-                None => quote_stmt!(cx, $ser).unwrap(),
-                Some(skip) => quote_stmt!(cx, if !$skip { $ser }).unwrap(),
+                None => ser,
+                Some(skip) => quote!(if !#skip { #ser }),
             }
         })
         .collect()
 }
 
 fn serialize_struct_visitor(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    structure_ty: P<ast::Ty>,
+    structure_ty: syn::Ty,
     fields: &[Field],
-    generics: &ast::Generics,
+    generics: &syn::Generics,
     is_enum: bool,
-    func: ast::Ident,
-) -> Vec<ast::Stmt> {
+    func: syn::Ident,
+) -> Vec<Tokens> {
     fields.iter()
         .filter(|&field| !field.attrs.skip_serializing())
         .map(|field| {
-            let ident = field.ident.expect("struct has unnamed field");
+            let ident = field.ident.clone().expect("struct has unnamed field");
             let mut field_expr = if is_enum {
-                quote_expr!(cx, $ident)
+                quote!(#ident)
             } else {
-                quote_expr!(cx, &self.$ident)
+                quote!(&self.#ident)
             };
 
-            let key_expr = name_expr(builder, field.attrs.name());
+            let key_expr = field.attrs.name().serialize_name();
 
             let skip = field.attrs.skip_serializing_if()
-                .map(|path| quote_expr!(cx, $path($field_expr)));
+                .map(|path| quote!(#path(#field_expr)));
 
             if let Some(path) = field.attrs.serialize_with() {
-                field_expr = wrap_serialize_with(cx, builder,
+                field_expr = wrap_serialize_with(
                     &structure_ty, generics, &field.ty, path, field_expr)
             }
 
-            let ser = quote_expr!(cx,
-                try!(_serializer.$func(&mut state, $key_expr, $field_expr));
-            );
+            let ser = quote! {
+                try!(_serializer.#func(&mut state, #key_expr, #field_expr));
+            };
 
             match skip {
-                None => quote_stmt!(cx, $ser).unwrap(),
-                Some(skip) => quote_stmt!(cx, if !$skip { $ser }).unwrap(),
+                None => ser,
+                Some(skip) => quote!(if !#skip { #ser }),
             }
         })
         .collect()
 }
 
 fn wrap_serialize_with(
-    cx: &ExtCtxt,
-    builder: &aster::AstBuilder,
-    item_ty: &P<ast::Ty>,
-    generics: &ast::Generics,
-    field_ty: &P<ast::Ty>,
-    path: &ast::Path,
-    value: P<ast::Expr>,
-) -> P<ast::Expr> {
+    item_ty: &syn::Ty,
+    generics: &syn::Generics,
+    field_ty: &syn::Ty,
+    path: &syn::Path,
+    value: Tokens,
+) -> Tokens {
     let where_clause = &generics.where_clause;
 
-    let wrapper_generics = builder.from_generics(generics.clone())
+    let wrapper_generics = aster::from_generics(generics.clone())
         .add_lifetime_bound("'__a")
         .lifetime_name("'__a")
         .build();
 
-    let wrapper_ty = builder.path()
+    let wrapper_ty = aster::path()
         .segment("__SerializeWith")
             .with_generics(wrapper_generics.clone())
             .build()
         .build();
 
-    quote_expr!(cx, {
-        struct __SerializeWith $wrapper_generics $where_clause {
-            value: &'__a $field_ty,
-            phantom: ::std::marker::PhantomData<$item_ty>,
-        }
+    quote! {
+        {
+            struct __SerializeWith #wrapper_generics #where_clause {
+                value: &'__a #field_ty,
+                phantom: ::std::marker::PhantomData<#item_ty>,
+            }
 
-        impl $wrapper_generics _serde::ser::Serialize for $wrapper_ty $where_clause {
-            fn serialize<__S>(&self, __s: &mut __S) -> ::std::result::Result<(), __S::Error>
-                where __S: _serde::ser::Serializer
-            {
-                $path(self.value, __s)
+            impl #wrapper_generics _serde::ser::Serialize for #wrapper_ty #where_clause {
+                fn serialize<__S>(&self, __s: &mut __S) -> ::std::result::Result<(), __S::Error>
+                    where __S: _serde::ser::Serializer
+                {
+                    #path(self.value, __s)
+                }
+            }
+
+            __SerializeWith {
+                value: #value,
+                phantom: ::std::marker::PhantomData::<#item_ty>,
             }
         }
-
-        __SerializeWith {
-            value: $value,
-            phantom: ::std::marker::PhantomData::<$item_ty>,
-        }
-    })
-}
-
-fn name_expr(
-    builder: &aster::AstBuilder,
-    name: &attr::Name,
-) -> P<ast::Expr> {
-    builder.expr().str(name.serialize_name())
+    }
 }
 
 // Serialization of an empty struct results in code like:
@@ -663,10 +552,10 @@ fn name_expr(
 //     serializer.serialize_struct_end(state)
 //
 // where we want to omit the `mut` to avoid a warning.
-fn mut_if(cx: &ExtCtxt, is_mut: bool) -> Vec<TokenTree> {
+fn mut_if(is_mut: bool) -> Option<Tokens> {
     if is_mut {
-        quote_tokens!(cx, mut)
+        Some(quote!(mut))
     } else {
-        Vec::new()
+        None
     }
 }
diff --git a/serde_codegen/src/span.rs b/serde_codegen/src/span.rs
deleted file mode 100644
index 5421868d..00000000
--- a/serde_codegen/src/span.rs
+++ /dev/null
@@ -1,43 +0,0 @@
-use syntax::ast;
-use syntax::codemap::{self, ExpnId, Span};
-use syntax::ext::base::{Annotatable, ExtCtxt};
-use syntax::fold::{self, Folder};
-use syntax::parse::token::intern;
-use syntax::ptr::P;
-
-pub fn record_expansion(
-    cx: &ExtCtxt,
-    item: P<ast::Item>,
-    derive: &str,
-) -> Annotatable {
-    let info = codemap::ExpnInfo {
-        call_site: codemap::DUMMY_SP,
-        callee: codemap::NameAndSpan {
-            format: codemap::MacroAttribute(intern(&format!("derive({})", derive))),
-            span: None,
-            allow_internal_unstable: false,
-        },
-    };
-    let expn_id = cx.codemap().record_expansion(info);
-
-    let mut respanner = Respanner { expn_id: expn_id };
-    let item = item.map(|item| respanner.fold_item_simple(item));
-    Annotatable::Item(item)
-}
-
-struct Respanner {
-    expn_id: ExpnId,
-}
-
-impl Folder for Respanner {
-    fn new_span(&mut self, span: Span) -> Span {
-        Span {
-            expn_id: self.expn_id,
-            .. span
-        }
-    }
-
-    fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
-        fold::noop_fold_mac(mac, self)
-    }
-}
diff --git a/serde_codegen_internals/Cargo.toml b/serde_codegen_internals/Cargo.toml
index 3219579d..2a621f1f 100644
--- a/serde_codegen_internals/Cargo.toml
+++ b/serde_codegen_internals/Cargo.toml
@@ -11,11 +11,8 @@ keywords = ["serde", "serialization"]
 include = ["Cargo.toml", "src/**/*.rs"]
 
 [features]
-default = ["with-syntex"]
 unstable-testing = ["clippy"]
-with-syntex = ["syntex_syntax", "syntex_errors"]
 
 [dependencies]
 clippy = { version = "^0.*", optional = true }
-syntex_syntax = { version = "^0.43.0", optional = true }
-syntex_errors = { version = "^0.43.0", optional = true }
+syn = "0.5"
diff --git a/serde_codegen_internals/src/ast.rs b/serde_codegen_internals/src/ast.rs
index dd79944f..d62ad807 100644
--- a/serde_codegen_internals/src/ast.rs
+++ b/serde_codegen_internals/src/ast.rs
@@ -1,17 +1,12 @@
-use syntax::ast;
-use syntax::codemap;
-use syntax::ext::base::ExtCtxt;
-use syntax::ptr::P;
-
+use syn;
 use attr;
-use Error;
+use Ctxt;
 
 pub struct Item<'a> {
-    pub ident: ast::Ident,
-    pub span: codemap::Span,
+    pub ident: syn::Ident,
     pub attrs: attr::Item,
     pub body: Body<'a>,
-    pub generics: &'a ast::Generics,
+    pub generics: &'a syn::Generics,
 }
 
 pub enum Body<'a> {
@@ -20,18 +15,16 @@ pub enum Body<'a> {
 }
 
 pub struct Variant<'a> {
-    pub ident: ast::Ident,
-    pub span: codemap::Span,
+    pub ident: syn::Ident,
     pub attrs: attr::Variant,
     pub style: Style,
     pub fields: Vec<Field<'a>>,
 }
 
 pub struct Field<'a> {
-    pub ident: Option<ast::Ident>,
-    pub span: codemap::Span,
+    pub ident: Option<syn::Ident>,
     pub attrs: attr::Field,
-    pub ty: &'a P<ast::Ty>,
+    pub ty: &'a syn::Ty,
 }
 
 pub enum Style {
@@ -42,33 +35,25 @@ pub enum Style {
 }
 
 impl<'a> Item<'a> {
-    pub fn from_ast(
-        cx: &ExtCtxt,
-        item: &'a ast::Item,
-    ) -> Result<Item<'a>, Error> {
+    pub fn from_ast(cx: &Ctxt, item: &'a syn::Item) -> Item<'a> {
         let attrs = attr::Item::from_ast(cx, item);
 
-        let (body, generics) = match item.node {
-            ast::ItemKind::Enum(ref enum_def, ref generics) => {
-                let variants = enum_from_ast(cx, enum_def);
-                (Body::Enum(variants), generics)
+        let body = match item.body {
+            syn::Body::Enum(ref variants) => {
+                Body::Enum(enum_from_ast(cx, variants))
             }
-            ast::ItemKind::Struct(ref variant_data, ref generics) => {
+            syn::Body::Struct(ref variant_data) => {
                 let (style, fields) = struct_from_ast(cx, variant_data);
-                (Body::Struct(style, fields), generics)
-            }
-            _ => {
-                return Err(Error::UnexpectedItemKind);
+                Body::Struct(style, fields)
             }
         };
 
-        Ok(Item {
-            ident: item.ident,
-            span: item.span,
+        Item {
+            ident: item.ident.clone(),
             attrs: attrs,
             body: body,
-            generics: generics,
-        })
+            generics: &item.generics,
+        }
     }
 }
 
@@ -86,16 +71,12 @@ impl<'a> Body<'a> {
     }
 }
 
-fn enum_from_ast<'a>(
-    cx: &ExtCtxt,
-    enum_def: &'a ast::EnumDef,
-) -> Vec<Variant<'a>> {
-    enum_def.variants.iter()
+fn enum_from_ast<'a>(cx: &Ctxt, variants: &'a [syn::Variant]) -> Vec<Variant<'a>> {
+    variants.iter()
         .map(|variant| {
-            let (style, fields) = struct_from_ast(cx, &variant.node.data);
+            let (style, fields) = struct_from_ast(cx, &variant.data);
             Variant {
-                ident: variant.node.name,
-                span: variant.span,
+                ident: variant.ident.clone(),
                 attrs: attr::Variant::from_ast(cx, variant),
                 style: style,
                 fields: fields,
@@ -104,36 +85,29 @@ fn enum_from_ast<'a>(
         .collect()
 }
 
-fn struct_from_ast<'a>(
-    cx: &ExtCtxt,
-    variant_data: &'a ast::VariantData,
-) -> (Style, Vec<Field<'a>>) {
-    match *variant_data {
-        ast::VariantData::Struct(ref fields, _) => {
+fn struct_from_ast<'a>(cx: &Ctxt, data: &'a syn::VariantData) -> (Style, Vec<Field<'a>>) {
+    match *data {
+        syn::VariantData::Struct(ref fields) => {
             (Style::Struct, fields_from_ast(cx, fields))
         }
-        ast::VariantData::Tuple(ref fields, _) if fields.len() == 1 => {
+        syn::VariantData::Tuple(ref fields) if fields.len() == 1 => {
             (Style::Newtype, fields_from_ast(cx, fields))
         }
-        ast::VariantData::Tuple(ref fields, _) => {
+        syn::VariantData::Tuple(ref fields) => {
             (Style::Tuple, fields_from_ast(cx, fields))
         }
-        ast::VariantData::Unit(_) => {
+        syn::VariantData::Unit => {
             (Style::Unit, Vec::new())
         }
     }
 }
 
-fn fields_from_ast<'a>(
-    cx: &ExtCtxt,
-    fields: &'a [ast::StructField],
-) -> Vec<Field<'a>> {
+fn fields_from_ast<'a>(cx: &Ctxt, fields: &'a [syn::Field]) -> Vec<Field<'a>> {
     fields.iter()
         .enumerate()
         .map(|(i, field)| {
             Field {
-                ident: field.ident,
-                span: field.span,
+                ident: field.ident.clone(),
                 attrs: attr::Field::from_ast(cx, i, field),
                 ty: &field.ty,
             }
diff --git a/serde_codegen_internals/src/attr.rs b/serde_codegen_internals/src/attr.rs
index a4dd2ce3..02b72b6c 100644
--- a/serde_codegen_internals/src/attr.rs
+++ b/serde_codegen_internals/src/attr.rs
@@ -1,15 +1,5 @@
-use std::rc::Rc;
-
-use syntax::ast;
-use syntax::attr::{self, HasAttrs};
-use syntax::codemap::{Span, Spanned, respan};
-use syntax::ext::base::ExtCtxt;
-use syntax::fold::Folder;
-use syntax::parse::parser::{Parser, PathStyle};
-use syntax::parse::token::{self, InternedString};
-use syntax::parse;
-use syntax::print::pprust::{lit_to_string, meta_item_to_string, meta_list_item_to_string};
-use syntax::tokenstream::{self, TokenTree};
+use Ctxt;
+use syn::{self, Ident};
 
 // This module handles parsing of `#[serde(...)]` attributes. The entrypoints
 // are `attr::Item::from_ast`, `attr::Variant::from_ast`, and
@@ -19,13 +9,14 @@ use syntax::tokenstream::{self, TokenTree};
 // user will see errors simultaneously for all bad attributes in the crate
 // rather than just the first.
 
-struct Attr<'a, 'b: 'a, T> {
-    cx: &'a ExtCtxt<'b>,
+struct Attr<'c, T> {
+    cx: &'c Ctxt,
     name: &'static str,
-    value: Option<Spanned<T>>,
+    value: Option<T>,
 }
-impl<'a, 'b, T> Attr<'a, 'b, T> {
-    fn none(cx: &'a ExtCtxt<'b>, name: &'static str) -> Self {
+
+impl<'c, T> Attr<'c, T> {
+    fn none(cx: &'c Ctxt, name: &'static str) -> Self {
         Attr {
             cx: cx,
             name: name,
@@ -33,47 +24,40 @@ impl<'a, 'b, T> Attr<'a, 'b, T> {
         }
     }
 
-    fn set(&mut self, span: Span, t: T) {
-        if let Some(Spanned { span: prev_span, .. }) = self.value {
-            let mut err = self.cx.struct_span_err(
-                span,
-                &format!("duplicate serde attribute `{}`", self.name));
-            err.span_help(prev_span, "previously set here");
-            err.emit();
+    fn set(&mut self, value: T) {
+        if self.value.is_some() {
+            self.cx.error(format!("duplicate serde attribute `{}`", self.name));
         } else {
-            self.value = Some(respan(span, t));
+            self.value = Some(value);
         }
     }
 
-    fn set_opt(&mut self, v: Option<Spanned<T>>) {
-        if let Some(v) = v {
-            self.set(v.span, v.node);
+    fn set_opt(&mut self, value: Option<T>) {
+        if let Some(value) = value {
+            self.set(value);
         }
     }
 
-    fn set_if_none(&mut self, span: Span, t: T) {
+    fn set_if_none(&mut self, value: T) {
         if self.value.is_none() {
-            self.value = Some(respan(span, t));
+            self.value = Some(value);
         }
     }
 
     fn get(self) -> Option<T> {
-        self.value.map(|spanned| spanned.node)
-    }
-
-    fn get_spanned(self) -> Option<Spanned<T>> {
         self.value
     }
 }
 
-struct BoolAttr<'a, 'b: 'a>(Attr<'a, 'b, ()>);
-impl<'a, 'b> BoolAttr<'a, 'b> {
-    fn none(cx: &'a ExtCtxt<'b>, name: &'static str) -> Self {
+struct BoolAttr<'c>(Attr<'c, ()>);
+
+impl<'c> BoolAttr<'c> {
+    fn none(cx: &'c Ctxt, name: &'static str) -> Self {
         BoolAttr(Attr::none(cx, name))
     }
 
-    fn set_true(&mut self, span: Span) {
-        self.0.set(span, ());
+    fn set_true(&mut self) {
+        self.0.set(());
     }
 
     fn get(&self) -> bool {
@@ -83,18 +67,18 @@ impl<'a, 'b> BoolAttr<'a, 'b> {
 
 #[derive(Debug)]
 pub struct Name {
-    serialize: InternedString,
-    deserialize: InternedString,
+    serialize: String,
+    deserialize: String,
 }
 
 impl Name {
     /// Return the container name for the container when serializing.
-    pub fn serialize_name(&self) -> InternedString {
+    pub fn serialize_name(&self) -> String {
         self.serialize.clone()
     }
 
     /// Return the container name for the container when deserializing.
-    pub fn deserialize_name(&self) -> InternedString {
+    pub fn deserialize_name(&self) -> String {
         self.deserialize.clone()
     }
 }
@@ -104,35 +88,30 @@ impl Name {
 pub struct Item {
     name: Name,
     deny_unknown_fields: bool,
-    ser_bound: Option<Vec<ast::WherePredicate>>,
-    de_bound: Option<Vec<ast::WherePredicate>>,
+    ser_bound: Option<Vec<syn::WherePredicate>>,
+    de_bound: Option<Vec<syn::WherePredicate>>,
 }
 
 impl Item {
     /// Extract out the `#[serde(...)]` attributes from an item.
-    pub fn from_ast(cx: &ExtCtxt, item: &ast::Item) -> Self {
+    pub fn from_ast(cx: &Ctxt, item: &syn::Item) -> Self {
         let mut ser_name = Attr::none(cx, "rename");
         let mut de_name = Attr::none(cx, "rename");
         let mut deny_unknown_fields = BoolAttr::none(cx, "deny_unknown_fields");
         let mut ser_bound = Attr::none(cx, "bound");
         let mut de_bound = Attr::none(cx, "bound");
 
-        let ident = item.ident.name.as_str();
-
-        for meta_items in item.attrs().iter().filter_map(get_serde_meta_items) {
+        for meta_items in item.attrs.iter().filter_map(get_serde_meta_items) {
             for meta_item in meta_items {
-                let span = meta_item.span;
-                match meta_item.node {
+                match meta_item {
                     // Parse `#[serde(rename="foo")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"rename" => {
-                        if let Ok(s) = get_str_from_lit(cx, name, lit) {
-                            ser_name.set(span, s.clone());
-                            de_name.set(span, s);
-                        }
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "rename" => {
+                        ser_name.set(lit.clone());
+                        de_name.set(lit.clone());
                     }
 
                     // Parse `#[serde(rename(serialize="foo", deserialize="bar"))]`
-                    ast::MetaItemKind::List(ref name, ref meta_items) if name == &"rename" => {
+                    syn::MetaItem::List(ref name, ref meta_items) if name == "rename" => {
                         if let Ok((ser, de)) = get_renames(cx, meta_items) {
                             ser_name.set_opt(ser);
                             de_name.set_opt(de);
@@ -140,20 +119,20 @@ impl Item {
                     }
 
                     // Parse `#[serde(deny_unknown_fields)]`
-                    ast::MetaItemKind::Word(ref name) if name == &"deny_unknown_fields" => {
-                        deny_unknown_fields.set_true(span);
+                    syn::MetaItem::Word(ref name) if name == "deny_unknown_fields" => {
+                        deny_unknown_fields.set_true();
                     }
 
                     // Parse `#[serde(bound="D: Serialize")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"bound" => {
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "bound" => {
                         if let Ok(where_predicates) = parse_lit_into_where(cx, name, lit) {
-                            ser_bound.set(span, where_predicates.clone());
-                            de_bound.set(span, where_predicates);
+                            ser_bound.set(where_predicates.clone());
+                            de_bound.set(where_predicates);
                         }
                     }
 
                     // Parse `#[serde(bound(serialize="D: Serialize", deserialize="D: Deserialize"))]`
-                    ast::MetaItemKind::List(ref name, ref meta_items) if name == &"bound" => {
+                    syn::MetaItem::List(ref name, ref meta_items) if name == "bound" => {
                         if let Ok((ser, de)) = get_where_predicates(cx, meta_items) {
                             ser_bound.set_opt(ser);
                             de_bound.set_opt(de);
@@ -161,10 +140,8 @@ impl Item {
                     }
 
                     _ => {
-                        cx.span_err(
-                            meta_item.span,
-                            &format!("unknown serde container attribute `{}`",
-                                     meta_item_to_string(&meta_item)));
+                        // TODO include name of attr
+                        cx.error("unknown serde container attribute");
                     }
                 }
             }
@@ -172,8 +149,8 @@ impl Item {
 
         Item {
             name: Name {
-                serialize: ser_name.get().unwrap_or(ident.clone()),
-                deserialize: de_name.get().unwrap_or(ident),
+                serialize: ser_name.get().unwrap_or_else(|| item.ident.to_string()),
+                deserialize: de_name.get().unwrap_or_else(|| item.ident.to_string()),
             },
             deny_unknown_fields: deny_unknown_fields.get(),
             ser_bound: ser_bound.get(),
@@ -189,11 +166,11 @@ impl Item {
         self.deny_unknown_fields
     }
 
-    pub fn ser_bound(&self) -> Option<&[ast::WherePredicate]> {
+    pub fn ser_bound(&self) -> Option<&[syn::WherePredicate]> {
         self.ser_bound.as_ref().map(|vec| &vec[..])
     }
 
-    pub fn de_bound(&self) -> Option<&[ast::WherePredicate]> {
+    pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> {
         self.de_bound.as_ref().map(|vec| &vec[..])
     }
 }
@@ -205,26 +182,21 @@ pub struct Variant {
 }
 
 impl Variant {
-    pub fn from_ast(cx: &ExtCtxt, variant: &ast::Variant) -> Self {
+    pub fn from_ast(cx: &Ctxt, variant: &syn::Variant) -> Self {
         let mut ser_name = Attr::none(cx, "rename");
         let mut de_name = Attr::none(cx, "rename");
 
-        let ident = variant.node.name.name.as_str();
-
-        for meta_items in variant.node.attrs.iter().filter_map(get_serde_meta_items) {
+        for meta_items in variant.attrs.iter().filter_map(get_serde_meta_items) {
             for meta_item in meta_items {
-                let span = meta_item.span;
-                match meta_item.node {
+                match meta_item {
                     // Parse `#[serde(rename="foo")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"rename" => {
-                        if let Ok(s) = get_str_from_lit(cx, name, lit) {
-                            ser_name.set(span, s.clone());
-                            de_name.set(span, s);
-                        }
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "rename" => {
+                        ser_name.set(lit.clone());
+                        de_name.set(lit.clone());
                     }
 
                     // Parse `#[serde(rename(serialize="foo", deserialize="bar"))]`
-                    ast::MetaItemKind::List(ref name, ref meta_items) if name == &"rename" => {
+                    syn::MetaItem::List(ref name, ref meta_items) if name == "rename" => {
                         if let Ok((ser, de)) = get_renames(cx, meta_items) {
                             ser_name.set_opt(ser);
                             de_name.set_opt(de);
@@ -232,10 +204,8 @@ impl Variant {
                     }
 
                     _ => {
-                        cx.span_err(
-                            meta_item.span,
-                            &format!("unknown serde variant attribute `{}`",
-                                     meta_item_to_string(&meta_item)));
+                        // TODO include attribute
+                        cx.error("unknown serde variant attribute");
                     }
                 }
             }
@@ -243,8 +213,8 @@ impl Variant {
 
         Variant {
             name: Name {
-                serialize: ser_name.get().unwrap_or(ident.clone()),
-                deserialize: de_name.get().unwrap_or(ident),
+                serialize: ser_name.get().unwrap_or_else(|| variant.ident.to_string()),
+                deserialize: de_name.get().unwrap_or_else(|| variant.ident.to_string()),
             },
         }
     }
@@ -260,12 +230,12 @@ pub struct Field {
     name: Name,
     skip_serializing: bool,
     skip_deserializing: bool,
-    skip_serializing_if: Option<ast::Path>,
+    skip_serializing_if: Option<syn::Path>,
     default: FieldDefault,
-    serialize_with: Option<ast::Path>,
-    deserialize_with: Option<ast::Path>,
-    ser_bound: Option<Vec<ast::WherePredicate>>,
-    de_bound: Option<Vec<ast::WherePredicate>>,
+    serialize_with: Option<syn::Path>,
+    deserialize_with: Option<syn::Path>,
+    ser_bound: Option<Vec<syn::WherePredicate>>,
+    de_bound: Option<Vec<syn::WherePredicate>>,
 }
 
 /// Represents the default to use for a field when deserializing.
@@ -276,14 +246,14 @@ pub enum FieldDefault {
     /// The default is given by `std::default::Default::default()`.
     Default,
     /// The default is given by this function.
-    Path(ast::Path),
+    Path(syn::Path),
 }
 
 impl Field {
     /// Extract out the `#[serde(...)]` attributes from a struct field.
-    pub fn from_ast(cx: &ExtCtxt,
+    pub fn from_ast(cx: &Ctxt,
                     index: usize,
-                    field: &ast::StructField) -> Self {
+                    field: &syn::Field) -> Self {
         let mut ser_name = Attr::none(cx, "rename");
         let mut de_name = Attr::none(cx, "rename");
         let mut skip_serializing = BoolAttr::none(cx, "skip_serializing");
@@ -296,24 +266,21 @@ impl Field {
         let mut de_bound = Attr::none(cx, "bound");
 
         let ident = match field.ident {
-            Some(ident) => ident.name.as_str(),
-            None => token::intern_and_get_ident(&index.to_string()),
+            Some(ref ident) => ident.to_string(),
+            None => index.to_string(),
         };
 
         for meta_items in field.attrs.iter().filter_map(get_serde_meta_items) {
             for meta_item in meta_items {
-                let span = meta_item.span;
-                match meta_item.node {
+                match meta_item {
                     // Parse `#[serde(rename="foo")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"rename" => {
-                        if let Ok(s) = get_str_from_lit(cx, name, lit) {
-                            ser_name.set(span, s.clone());
-                            de_name.set(span, s);
-                        }
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "rename" => {
+                        ser_name.set(lit.clone());
+                        de_name.set(lit.clone());
                     }
 
                     // Parse `#[serde(rename(serialize="foo", deserialize="bar"))]`
-                    ast::MetaItemKind::List(ref name, ref meta_items) if name == &"rename" => {
+                    syn::MetaItem::List(ref name, ref meta_items) if name == "rename" => {
                         if let Ok((ser, de)) = get_renames(cx, meta_items) {
                             ser_name.set_opt(ser);
                             de_name.set_opt(de);
@@ -321,58 +288,58 @@ impl Field {
                     }
 
                     // Parse `#[serde(default)]`
-                    ast::MetaItemKind::Word(ref name) if name == &"default" => {
-                        default.set(span, FieldDefault::Default);
+                    syn::MetaItem::Word(ref name) if name == "default" => {
+                        default.set(FieldDefault::Default);
                     }
 
                     // Parse `#[serde(default="...")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"default" => {
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "default" => {
                         if let Ok(path) = parse_lit_into_path(cx, name, lit) {
-                            default.set(span, FieldDefault::Path(path));
+                            default.set(FieldDefault::Path(path));
                         }
                     }
 
                     // Parse `#[serde(skip_serializing)]`
-                    ast::MetaItemKind::Word(ref name) if name == &"skip_serializing" => {
-                        skip_serializing.set_true(span);
+                    syn::MetaItem::Word(ref name) if name == "skip_serializing" => {
+                        skip_serializing.set_true();
                     }
 
                     // Parse `#[serde(skip_deserializing)]`
-                    ast::MetaItemKind::Word(ref name) if name == &"skip_deserializing" => {
-                        skip_deserializing.set_true(span);
+                    syn::MetaItem::Word(ref name) if name == "skip_deserializing" => {
+                        skip_deserializing.set_true();
                     }
 
                     // Parse `#[serde(skip_serializing_if="...")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"skip_serializing_if" => {
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "skip_serializing_if" => {
                         if let Ok(path) = parse_lit_into_path(cx, name, lit) {
-                            skip_serializing_if.set(span, path);
+                            skip_serializing_if.set(path);
                         }
                     }
 
                     // Parse `#[serde(serialize_with="...")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"serialize_with" => {
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "serialize_with" => {
                         if let Ok(path) = parse_lit_into_path(cx, name, lit) {
-                            serialize_with.set(span, path);
+                            serialize_with.set(path);
                         }
                     }
 
                     // Parse `#[serde(deserialize_with="...")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"deserialize_with" => {
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "deserialize_with" => {
                         if let Ok(path) = parse_lit_into_path(cx, name, lit) {
-                            deserialize_with.set(span, path);
+                            deserialize_with.set(path);
                         }
                     }
 
                     // Parse `#[serde(bound="D: Serialize")]`
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"bound" => {
+                    syn::MetaItem::NameValue(ref name, ref lit) if name == "bound" => {
                         if let Ok(where_predicates) = parse_lit_into_where(cx, name, lit) {
-                            ser_bound.set(span, where_predicates.clone());
-                            de_bound.set(span, where_predicates);
+                            ser_bound.set(where_predicates.clone());
+                            de_bound.set(where_predicates);
                         }
                     }
 
                     // Parse `#[serde(bound(serialize="D: Serialize", deserialize="D: Deserialize"))]`
-                    ast::MetaItemKind::List(ref name, ref meta_items) if name == &"bound" => {
+                    syn::MetaItem::List(ref name, ref meta_items) if name == "bound" => {
                         if let Ok((ser, de)) = get_where_predicates(cx, meta_items) {
                             ser_bound.set_opt(ser);
                             de_bound.set_opt(de);
@@ -380,10 +347,8 @@ impl Field {
                     }
 
                     _ => {
-                        cx.span_err(
-                            meta_item.span,
-                            &format!("unknown serde field attribute `{}`",
-                                     meta_item_to_string(&meta_item)));
+                        // TODO include attribute
+                        cx.error("unknown serde field attribute");
                     }
                 }
             }
@@ -391,8 +356,8 @@ impl Field {
 
         // Is skip_deserializing, initialize the field to Default::default()
         // unless a different default is specified by `#[serde(default="...")]`
-        if let Some(Spanned { span, .. }) = skip_deserializing.0.value {
-            default.set_if_none(span, FieldDefault::Default);
+        if skip_deserializing.0.value.is_some() {
+            default.set_if_none(FieldDefault::Default);
         }
 
         Field {
@@ -423,7 +388,7 @@ impl Field {
         self.skip_deserializing
     }
 
-    pub fn skip_serializing_if(&self) -> Option<&ast::Path> {
+    pub fn skip_serializing_if(&self) -> Option<&syn::Path> {
         self.skip_serializing_if.as_ref()
     }
 
@@ -431,230 +396,95 @@ impl Field {
         &self.default
     }
 
-    pub fn serialize_with(&self) -> Option<&ast::Path> {
+    pub fn serialize_with(&self) -> Option<&syn::Path> {
         self.serialize_with.as_ref()
     }
 
-    pub fn deserialize_with(&self) -> Option<&ast::Path> {
+    pub fn deserialize_with(&self) -> Option<&syn::Path> {
         self.deserialize_with.as_ref()
     }
 
-    pub fn ser_bound(&self) -> Option<&[ast::WherePredicate]> {
+    pub fn ser_bound(&self) -> Option<&[syn::WherePredicate]> {
         self.ser_bound.as_ref().map(|vec| &vec[..])
     }
 
-    pub fn de_bound(&self) -> Option<&[ast::WherePredicate]> {
+    pub fn de_bound(&self) -> Option<&[syn::WherePredicate]> {
         self.de_bound.as_ref().map(|vec| &vec[..])
     }
 }
 
-type SerAndDe<T> = (Option<Spanned<T>>, Option<Spanned<T>>);
+type SerAndDe<T> = (Option<T>, Option<T>);
 
 fn get_ser_and_de<T, F>(
-    cx: &ExtCtxt,
+    cx: &Ctxt,
     attribute: &'static str,
-    items: &[ast::NestedMetaItem],
+    items: &[syn::MetaItem],
     f: F
 ) -> Result<SerAndDe<T>, ()>
-    where F: Fn(&ExtCtxt, &str, &ast::Lit) -> Result<T, ()>,
+    where F: Fn(&Ctxt, &Ident, &str) -> Result<T, ()>,
 {
     let mut ser_item = Attr::none(cx, attribute);
     let mut de_item = Attr::none(cx, attribute);
 
     for item in items {
-        match item.node {
-            ast::NestedMetaItemKind::MetaItem(ref meta_item) => {
-                match meta_item.node {
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"serialize" => {
-                        if let Ok(v) = f(cx, name, lit) {
-                            ser_item.set(item.span, v);
-                        }
-                    }
+        match *item {
+            syn::MetaItem::NameValue(ref name, ref lit) if name == "serialize" => {
+                if let Ok(v) = f(cx, name, lit) {
+                    ser_item.set(v);
+                }
+            }
 
-                    ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"deserialize" => {
-                        if let Ok(v) = f(cx, name, lit) {
-                            de_item.set(item.span, v);
-                        }
-                    }
-
-                    _ => {
-                        cx.span_err(
-                            item.span,
-                            &format!("unknown {} attribute `{}`",
-                                    attribute,
-                                    meta_item_to_string(meta_item)));
-
-                        return Err(());
-                    }
+            syn::MetaItem::NameValue(ref name, ref lit) if name == "deserialize" => {
+                if let Ok(v) = f(cx, name, lit) {
+                    de_item.set(v);
                 }
             }
 
             _ => {
-                cx.span_err(
-                    item.span,
-                    &format!("unknown {} attribute `{}`",
-                             attribute,
-                             meta_list_item_to_string(item)));
-
+                cx.error(format!("bad {} attribute", attribute));
                 return Err(());
             }
         }
     }
 
-    Ok((ser_item.get_spanned(), de_item.get_spanned()))
+    Ok((ser_item.get(), de_item.get()))
 }
 
 fn get_renames(
-    cx: &ExtCtxt,
-    items: &[ast::NestedMetaItem],
-) -> Result<SerAndDe<InternedString>, ()> {
-    get_ser_and_de(cx, "rename", items, get_str_from_lit)
+    cx: &Ctxt,
+    items: &[syn::MetaItem],
+) -> Result<SerAndDe<String>, ()> {
+    get_ser_and_de(cx, "rename", items, |_, _, s| Ok(s.to_owned()))
 }
 
 fn get_where_predicates(
-    cx: &ExtCtxt,
-    items: &[ast::NestedMetaItem],
-) -> Result<SerAndDe<Vec<ast::WherePredicate>>, ()> {
+    cx: &Ctxt,
+    items: &[syn::MetaItem],
+) -> Result<SerAndDe<Vec<syn::WherePredicate>>, ()> {
     get_ser_and_de(cx, "bound", items, parse_lit_into_where)
 }
 
-pub fn get_serde_meta_items(attr: &ast::Attribute) -> Option<Vec<ast::MetaItem>> {
-    match attr.node.value.node {
-        ast::MetaItemKind::List(ref name, ref items) if name == &"serde" => {
-            attr::mark_used(attr);
-            Some(items.iter().filter_map(|item| {
-                match item.node {
-                    ast::NestedMetaItemKind::MetaItem(ref meta_item) => {
-                        Some((*meta_item.clone()).clone())
-                    }
-                    _ => None,
-                }
-            }).collect())
+pub fn get_serde_meta_items(attr: &syn::Attribute) -> Option<Vec<syn::MetaItem>> {
+    match attr.value {
+        syn::MetaItem::List(ref name, ref items) if name == "serde" => {
+            Some(items.iter().cloned().collect())
         }
         _ => None
     }
 }
 
-/// This syntax folder rewrites tokens to say their spans are coming from a macro context.
-struct Respanner<'a, 'b: 'a> {
-    cx: &'a ExtCtxt<'b>,
+fn parse_lit_into_path(cx: &Ctxt, name: &Ident, lit: &str) -> Result<syn::Path, ()> {
+    // TODO handle error
+    Ok(syn::parse_path(lit).unwrap())
 }
 
-impl<'a, 'b> Folder for Respanner<'a, 'b> {
-    fn fold_tt(&mut self, tt: &TokenTree) -> TokenTree {
-        match *tt {
-            TokenTree::Token(span, ref tok) => {
-                TokenTree::Token(
-                    self.new_span(span),
-                    self.fold_token(tok.clone())
-                )
-            }
-            TokenTree::Delimited(span, ref delimed) => {
-                TokenTree::Delimited(
-                    self.new_span(span),
-                    Rc::new(tokenstream::Delimited {
-                        delim: delimed.delim,
-                        open_span: delimed.open_span,
-                        tts: self.fold_tts(&delimed.tts),
-                        close_span: delimed.close_span,
-                    })
-                )
-            }
-            TokenTree::Sequence(span, ref seq) => {
-                TokenTree::Sequence(
-                    self.new_span(span),
-                    Rc::new(tokenstream::SequenceRepetition {
-                        tts: self.fold_tts(&seq.tts),
-                        separator: seq.separator.clone().map(|tok| self.fold_token(tok)),
-                        ..**seq
-                    })
-                )
-            }
-        }
-    }
-
-    fn new_span(&mut self, span: Span) -> Span {
-        Span {
-            lo: span.lo,
-            hi: span.hi,
-            expn_id: self.cx.backtrace(),
-        }
-    }
-}
-
-fn get_str_from_lit(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<InternedString, ()> {
-    match lit.node {
-        ast::LitKind::Str(ref s, _) => Ok(s.clone()),
-        _ => {
-            cx.span_err(
-                lit.span,
-                &format!("serde annotation `{}` must be a string, not `{}`",
-                         name,
-                         lit_to_string(lit)));
-
-            Err(())
-        }
-    }
-}
-
-// If we just parse a string literal from an attibute, any syntax errors in the
-// source will only have spans that point inside the string and not back to the
-// attribute. So to have better error reporting, we'll first parse the string
-// into a token tree. Then we'll update those spans to say they're coming from a
-// macro context that originally came from the attribnute, and then finally
-// parse them into an expression or where-clause.
-fn parse_string_via_tts<T, F>(cx: &ExtCtxt, name: &str, string: String, action: F) -> Result<T, ()>
-    where F: for<'a> Fn(&'a mut Parser) -> parse::PResult<'a, T>,
-{
-    let tts = panictry!(parse::parse_tts_from_source_str(
-        format!("<serde {} expansion>", name),
-        string,
-        cx.cfg(),
-        cx.parse_sess()));
-
-    // Respan the spans to say they are all coming from this macro.
-    let tts = Respanner { cx: cx }.fold_tts(&tts);
-
-    let mut parser = parse::new_parser_from_tts(cx.parse_sess(), cx.cfg(), tts);
-
-    let path = match action(&mut parser) {
-        Ok(path) => path,
-        Err(mut e) => {
-            e.emit();
-            return Err(());
-        }
-    };
-
-    // Make sure to error out if there are trailing characters in the stream.
-    match parser.expect(&token::Eof) {
-        Ok(()) => { }
-        Err(mut e) => {
-            e.emit();
-            return Err(());
-        }
-    }
-
-    Ok(path)
-}
-
-fn parse_lit_into_path(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<ast::Path, ()> {
-    let string = try!(get_str_from_lit(cx, name, lit)).to_string();
-
-    parse_string_via_tts(cx, name, string, |parser| {
-        parser.parse_path(PathStyle::Type)
-    })
-}
-
-fn parse_lit_into_where(cx: &ExtCtxt, name: &str, lit: &ast::Lit) -> Result<Vec<ast::WherePredicate>, ()> {
-    let string = try!(get_str_from_lit(cx, name, lit));
-    if string.is_empty() {
+fn parse_lit_into_where(cx: &Ctxt, name: &Ident, lit: &str) -> Result<Vec<syn::WherePredicate>, ()> {
+    if lit.is_empty() {
         return Ok(Vec::new());
     }
 
-    let where_string = format!("where {}", string);
+    let where_string = format!("where {}", lit);
 
-    parse_string_via_tts(cx, name, where_string, |parser| {
-        let where_clause = try!(parser.parse_where_clause());
-        Ok(where_clause.predicates)
-    })
+    // TODO handle error
+    Ok(syn::parse_where_clause(&where_string).unwrap().predicates)
 }
diff --git a/serde_codegen_internals/src/ctxt.rs b/serde_codegen_internals/src/ctxt.rs
new file mode 100644
index 00000000..a516aec8
--- /dev/null
+++ b/serde_codegen_internals/src/ctxt.rs
@@ -0,0 +1,29 @@
+use std::fmt::Display;
+use std::cell::Cell;
+
+#[derive(Default)]
+pub struct Ctxt {
+    err_count: Cell<usize>,
+}
+
+impl Ctxt {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    pub fn error<T: Display>(&self, msg: T) {
+        println!("{}", msg);
+        self.err_count.set(self.err_count.get() + 1);
+    }
+}
+
+impl Drop for Ctxt {
+    fn drop(&mut self) {
+        let err_count = self.err_count.get();
+        if err_count == 1 {
+            panic!("1 error");
+        } else if err_count > 1 {
+            panic!("{} errors", err_count);
+        }
+    }
+}
diff --git a/serde_codegen_internals/src/error.rs b/serde_codegen_internals/src/error.rs
deleted file mode 100644
index 08337c0b..00000000
--- a/serde_codegen_internals/src/error.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-use std::error;
-use std::fmt;
-
-#[derive(Debug)]
-pub enum Error {
-    UnexpectedItemKind,
-}
-
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "expected a struct or enum")
-    }
-}
-
-impl error::Error for Error {
-    fn description(&self) -> &str {
-        "expected a struct or enum"
-    }
-}
diff --git a/serde_codegen_internals/src/lib.rs b/serde_codegen_internals/src/lib.rs
index 89f20aa6..0f37f5fa 100644
--- a/serde_codegen_internals/src/lib.rs
+++ b/serde_codegen_internals/src/lib.rs
@@ -1,21 +1,10 @@
 #![cfg_attr(feature = "clippy", plugin(clippy))]
 #![cfg_attr(feature = "clippy", feature(plugin))]
-#![cfg_attr(not(feature = "with-syntex"), feature(rustc_private, plugin))]
 
-#[cfg(feature = "with-syntex")]
-#[macro_use]
-extern crate syntex_syntax as syntax;
-#[cfg(feature = "with-syntex")]
-extern crate syntex_errors as errors;
-
-#[cfg(not(feature = "with-syntex"))]
-#[macro_use]
-extern crate syntax;
-#[cfg(not(feature = "with-syntex"))]
-extern crate rustc_errors as errors;
+extern crate syn;
 
 pub mod ast;
 pub mod attr;
 
-mod error;
-pub use error::Error;
+mod ctxt;
+pub use ctxt::Ctxt;
diff --git a/serde_derive/Cargo.toml b/serde_derive/Cargo.toml
index 66930b14..da38783d 100644
--- a/serde_derive/Cargo.toml
+++ b/serde_derive/Cargo.toml
@@ -14,8 +14,11 @@ include = ["Cargo.toml", "src/**/*.rs"]
 name = "serde_derive"
 rustc-macro = true
 
-[dependencies]
-serde_codegen = { version = "=0.8.8", path = "../serde_codegen" }
+[dependencies.serde_codegen]
+version = "=0.8.8"
+path = "../serde_codegen"
+default-features = false
+features = ["with-syn"]
 
 [dev-dependencies]
 fnv = "1.0"
diff --git a/serde_derive/src/lib.rs b/serde_derive/src/lib.rs
index aa7bba60..5c80708a 100644
--- a/serde_derive/src/lib.rs
+++ b/serde_derive/src/lib.rs
@@ -9,13 +9,13 @@ use rustc_macro::TokenStream;
 #[rustc_macro_derive(Serialize)]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
     let item = format!("#[derive(Serialize)]\n{}", input);
-    let expanded = serde_codegen::expand_str(&item).unwrap();
+    let expanded = serde_codegen::expand_single_item(&item);
     expanded.parse().unwrap()
 }
 
 #[rustc_macro_derive(Deserialize)]
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
     let item = format!("#[derive(Deserialize)]\n{}", input);
-    let expanded = serde_codegen::expand_str(&item).unwrap();
+    let expanded = serde_codegen::expand_single_item(&item);
     expanded.parse().unwrap()
 }