diff --git a/serde_macros/src/lib.rs b/serde_macros/src/lib.rs
index 66685a2a..20e2247e 100644
--- a/serde_macros/src/lib.rs
+++ b/serde_macros/src/lib.rs
@@ -17,7 +17,6 @@ use syntax::ast::{
     ItemStruct,
     Expr,
     MutMutable,
-    LitNil,
     LitStr,
     StructField,
     Variant,
@@ -25,7 +24,7 @@ use syntax::ast::{
 use syntax::ast;
 use syntax::attr;
 use syntax::codemap::Span;
-use syntax::ext::base::{ExtCtxt, ItemDecorator};
+use syntax::ext::base::{ExtCtxt, Decorator};
 use syntax::ext::build::AstBuilder;
 use syntax::ext::deriving::generic::{
     EnumMatching,
@@ -61,11 +60,11 @@ use rustc::plugin::Registry;
 pub fn plugin_registrar(reg: &mut Registry) {
     reg.register_syntax_extension(
         token::intern("deriving_serializable"),
-        ItemDecorator(box expand_deriving_serializable));
+        Decorator(box expand_deriving_serializable));
 
     reg.register_syntax_extension(
         token::intern("deriving_deserializable"),
-        ItemDecorator(box expand_deriving_deserializable));
+        Decorator(box expand_deriving_deserializable));
 }
 
 fn expand_deriving_serializable(cx: &mut ExtCtxt,
@@ -137,7 +136,7 @@ fn serializable_substructure(cx: &ExtCtxt,
                 );
                 let len = fields.len();
 
-                let mut stmts: Vec<P<ast::Stmt>> = definition.fields.iter()
+                let stmts: Vec<P<ast::Stmt>> = definition.fields.iter()
                     .zip(fields.iter())
                     .enumerate()
                     .map(|(i, (def, &FieldInfo { name, ref self_, span, .. }))| {
@@ -178,7 +177,7 @@ fn serializable_substructure(cx: &ExtCtxt,
 
             let stmts: Vec<P<ast::Stmt>> = definition.variants.iter()
                 .zip(fields.iter())
-                .map(|(def, &FieldInfo { ref self_, span, .. })| {
+                .map(|(def, &FieldInfo { ref self_, .. })| {
                     let _serial_name = find_serial_name(def.node.attrs.iter());
                     quote_stmt!(
                         cx,
@@ -336,7 +335,7 @@ fn deserialize_struct_from_struct(
     fields: &StaticFields,
     deserializer: P<ast::Expr>
 ) -> P<ast::Expr> {
-    let expect_struct_field = cx.ident_of("expect_struct_field");
+    //let expect_struct_field = cx.ident_of("expect_struct_field");
 
     let call = deserializable_static_fields(
         cx,
@@ -375,7 +374,7 @@ fn deserialize_struct_from_map(
 
     // Declare each field.
     let let_fields: Vec<P<ast::Stmt>> = fields.iter()
-        .map(|&(name, span)| {
+        .map(|&(name, _)| {
             quote_stmt!(cx, let mut $name = None)
         })
         .collect();
@@ -494,7 +493,7 @@ fn deserialize_enum(
                 name,
                 serial_names.as_slice(),
                 parts,
-                |cx, span, _| {
+                |cx, _, _| {
                     quote_expr!(cx, try!($deserializer.expect_enum_elt()))
                 }
             );
diff --git a/src/de.rs b/src/de.rs
index 618b9f49..340348dc 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -13,6 +13,8 @@ use std::gc::{GC, Gc};
 use std::hash::Hash;
 use std::num;
 use std::rc::Rc;
+use std::option;
+use std::string;
 use std::sync::Arc;
 
 #[deriving(Clone, PartialEq, Show)]
@@ -33,7 +35,7 @@ pub enum Token {
     F64(f64),
     Char(char),
     Str(&'static str),
-    String(String),
+    String(string::String),
     Option(bool),
 
     TupleStart(uint),
@@ -293,7 +295,7 @@ pub trait Deserializer<E>: Iterator<Result<Token, E>> {
     }
 
     #[inline]
-    fn expect_string(&mut self, token: Token) -> Result<String, E> {
+    fn expect_string(&mut self, token: Token) -> Result<string::String, E> {
         match token {
             Char(value) => Ok(value.to_string()),
             Str(value) => Ok(value.to_string()),
@@ -305,7 +307,7 @@ pub trait Deserializer<E>: Iterator<Result<Token, E>> {
     #[inline]
     fn expect_option<
         T: Deserializable<Self, E>
-    >(&mut self, token: Token) -> Result<Option<T>, E> {
+    >(&mut self, token: Token) -> Result<option::Option<T>, E> {
         match token {
             Option(false) => Ok(None),
             Option(true) => {
@@ -429,7 +431,7 @@ pub trait Deserializer<E>: Iterator<Result<Token, E>> {
     #[inline]
     fn expect_seq_elt_or_end<
         T: Deserializable<Self, E>
-    >(&mut self) -> Result<Option<T>, E> {
+    >(&mut self) -> Result<option::Option<T>, E> {
         match try!(self.expect_token()) {
             End => Ok(None),
             token => {
@@ -473,7 +475,7 @@ pub trait Deserializer<E>: Iterator<Result<Token, E>> {
     fn expect_map_elt_or_end<
         K: Deserializable<Self, E>,
         V: Deserializable<Self, E>
-    >(&mut self) -> Result<Option<(K, V)>, E> {
+    >(&mut self) -> Result<option::Option<(K, V)>, E> {
         match try!(self.expect_token()) {
             End => Ok(None),
             token => {
@@ -513,7 +515,7 @@ pub trait Deserializer<E>: Iterator<Result<Token, E>> {
 struct SeqDeserializer<'a, D: 'a, E> {
     d: &'a mut D,
     len: uint,
-    err: Option<E>,
+    err: option::Option<E>,
 }
 
 impl<
@@ -523,7 +525,7 @@ impl<
     T: Deserializable<D, E>
 > Iterator<T> for SeqDeserializer<'a, D, E> {
     #[inline]
-    fn next(&mut self) -> Option<T> {
+    fn next(&mut self) -> option::Option<T> {
         match self.d.expect_seq_elt_or_end() {
             Ok(next) => next,
             Err(err) => {
@@ -534,7 +536,7 @@ impl<
     }
 
     #[inline]
-    fn size_hint(&self) -> (uint, Option<uint>) {
+    fn size_hint(&self) -> (uint, option::Option<uint>) {
         (self.len, Some(self.len))
     }
 }
@@ -544,7 +546,7 @@ impl<
 struct MapDeserializer<'a, D:'a, E> {
     d: &'a mut D,
     len: uint,
-    err: Option<E>,
+    err: option::Option<E>,
 }
 
 impl<
@@ -555,7 +557,7 @@ impl<
     V: Deserializable<D, E>
 > Iterator<(K, V)> for MapDeserializer<'a, D, E> {
     #[inline]
-    fn next(&mut self) -> Option<(K, V)> {
+    fn next(&mut self) -> option::Option<(K, V)> {
         match self.d.expect_map_elt_or_end() {
             Ok(next) => next,
             Err(err) => {
@@ -566,7 +568,7 @@ impl<
     }
 
     #[inline]
-    fn size_hint(&self) -> (uint, Option<uint>) {
+    fn size_hint(&self) -> (uint, option::Option<uint>) {
         (self.len, Some(self.len))
     }
 }
@@ -611,7 +613,7 @@ impl_deserializable!(f32, expect_num)
 impl_deserializable!(f64, expect_num)
 impl_deserializable!(char, expect_char)
 impl_deserializable!(&'static str, expect_str)
-impl_deserializable!(String, expect_string)
+impl_deserializable!(string::String, expect_string)
 
 //////////////////////////////////////////////////////////////////////////////
 
@@ -665,9 +667,9 @@ impl<
     D: Deserializer<E>,
     E,
     T: Deserializable<D ,E>
-> Deserializable<D, E> for Option<T> {
+> Deserializable<D, E> for option::Option<T> {
     #[inline]
-    fn deserialize_token(d: &mut D, token: Token) -> Result<Option<T>, E> {
+    fn deserialize_token(d: &mut D, token: Token) -> Result<option::Option<T>, E> {
         d.expect_option(token)
     }
 }
diff --git a/src/json/builder.rs b/src/json/builder.rs
index 16fc1e47..d2af7b1c 100644
--- a/src/json/builder.rs
+++ b/src/json/builder.rs
@@ -11,7 +11,7 @@
 use std::collections::TreeMap;
 use std::str::StrAllocating;
 
-use super::{Json, List, Object, ToJson};
+use super::{Json, JsonObject, List, Object, ToJson};
 
 pub struct ListBuilder {
     list: Vec<Json>,
@@ -44,7 +44,7 @@ impl ListBuilder {
 }
 
 pub struct ObjectBuilder {
-    object: Object,
+    object: JsonObject,
 }
 
 impl ObjectBuilder {
diff --git a/src/json/mod.rs b/src/json/mod.rs
index ba709910..7f96064b 100644
--- a/src/json/mod.rs
+++ b/src/json/mod.rs
@@ -274,7 +274,7 @@ use std::num::{FPNaN, FPInfinite};
 use std::num;
 use std::str::ScalarValue;
 use std::str;
-use std::string::String;
+use std::string;
 use std::vec::Vec;
 use std::vec;
 
@@ -291,13 +291,13 @@ pub enum Json {
     Boolean(bool),
     Integer(i64),
     Floating(f64),
-    String(String),
-    List(List),
-    Object(Object),
+    String(string::String),
+    List(JsonList),
+    Object(JsonObject),
 }
 
-pub type List = Vec<Json>;
-pub type Object = TreeMap<String, Json>;
+pub type JsonList = Vec<Json>;
+pub type JsonObject = TreeMap<string::String, Json>;
 
 impl Json {
     /// Serializes a json value into an io::writer.  Uses a single line.
@@ -314,7 +314,7 @@ impl Json {
     }
 
     /// Serializes a json value into a string
-    pub fn to_pretty_string(&self) -> String {
+    pub fn to_pretty_string(&self) -> string::String {
         let mut wr = MemWriter::new();
         self.to_pretty_writer(wr.by_ref()).unwrap();
         str::from_utf8(wr.unwrap().as_slice()).unwrap().to_string()
@@ -322,7 +322,7 @@ impl Json {
 
      /// If the Json value is an Object, returns the value associated with the provided key.
     /// Otherwise, returns None.
-    pub fn find<'a>(&'a self, key: &String) -> Option<&'a Json>{
+    pub fn find<'a>(&'a self, key: &string::String) -> Option<&'a Json>{
         match self {
             &Object(ref map) => map.find(key),
             _ => None
@@ -332,7 +332,7 @@ impl Json {
     /// Attempts to get a nested Json Object for each key in `keys`.
     /// If any key is found not to exist, find_path will return None.
     /// Otherwise, it will return the Json value associated with the final key.
-    pub fn find_path<'a>(&'a self, keys: &[&String]) -> Option<&'a Json>{
+    pub fn find_path<'a>(&'a self, keys: &[&string::String]) -> Option<&'a Json>{
         let mut target = self;
         for key in keys.iter() {
             match target.find(*key) {
@@ -346,7 +346,7 @@ impl Json {
     /// If the Json value is an Object, performs a depth-first search until
     /// a value associated with the provided key is found. If no value is found
     /// or the Json value is not an Object, returns None.
-    pub fn search<'a>(&'a self, key: &String) -> Option<&'a Json> {
+    pub fn search<'a>(&'a self, key: &string::String) -> Option<&'a Json> {
         match self {
             &Object(ref map) => {
                 match map.find(key) {
@@ -374,7 +374,7 @@ impl Json {
 
     /// If the Json value is an Object, returns the associated TreeMap.
     /// Returns None otherwise.
-    pub fn as_object<'a>(&'a self) -> Option<&'a Object> {
+    pub fn as_object<'a>(&'a self) -> Option<&'a JsonObject> {
         match *self {
             Object(ref map) => Some(map),
             _ => None
@@ -388,7 +388,7 @@ impl Json {
 
     /// If the Json value is a List, returns the associated vector.
     /// Returns None otherwise.
-    pub fn as_list<'a>(&'a self) -> Option<&'a List> {
+    pub fn as_list<'a>(&'a self) -> Option<&'a JsonList> {
         match *self {
             List(ref list) => Some(list),
             _ => None
@@ -564,7 +564,7 @@ impl<D: de::Deserializer<E>, E> de::Deserializable<D, E> for Json {
 enum JsonDeserializerState {
     JsonDeserializerValueState(Json),
     JsonDeserializerListState(vec::MoveItems<Json>),
-    JsonDeserializerObjectState(treemap::MoveEntries<String, Json>),
+    JsonDeserializerObjectState(treemap::MoveEntries<string::String, Json>),
     JsonDeserializerEndState,
 }
 
@@ -595,12 +595,12 @@ impl Iterator<Result<de::Token, ParserError>> for JsonDeserializer {
                         String(x) => de::String(x),
                         List(x) => {
                             let len = x.len();
-                            self.stack.push(JsonDeserializerListState(x.move_iter()));
+                            self.stack.push(JsonDeserializerListState(x.into_iter()));
                             de::SeqStart(len)
                         }
                         Object(x) => {
                             let len = x.len();
-                            self.stack.push(JsonDeserializerObjectState(x.move_iter()));
+                            self.stack.push(JsonDeserializerObjectState(x.into_iter()));
                             de::MapStart(len)
                         }
                     };
@@ -716,7 +716,7 @@ impl de::Deserializer<ParserError> for JsonDeserializer {
 
                 self.stack.push(JsonDeserializerEndState);
 
-                for field in fields.move_iter().rev() {
+                for field in fields.into_iter().rev() {
                     self.stack.push(JsonDeserializerValueState(field));
                 }
 
@@ -786,9 +786,9 @@ pub enum ParserError {
     /// msg, line, col
     SyntaxError(ErrorCode, uint, uint),
     IoError(io::IoErrorKind, &'static str),
-    ExpectedError(String, String),
-    MissingFieldError(String),
-    UnknownVariantError(String),
+    ExpectedError(string::String, string::String),
+    MissingFieldError(string::String),
+    UnknownVariantError(string::String),
 }
 
 // Builder and Parser have the same errors.
@@ -1422,9 +1422,9 @@ pub fn to_vec<
 #[inline]
 pub fn to_string<
     T: ser::Serializable<Serializer<MemWriter>, io::IoError>
->(value: &T) -> Result<String, Vec<u8>> {
+>(value: &T) -> Result<string::String, Vec<u8>> {
     let buf = to_vec(value);
-    String::from_utf8(buf)
+    string::String::from_utf8(buf)
 }
 
 /// Encode the specified struct into a json `[u8]` buffer.
@@ -1440,9 +1440,9 @@ pub fn to_pretty_vec<
 /// Encode the specified struct into a json `String` buffer.
 pub fn to_pretty_string<
     T: ser::Serializable<PrettySerializer<MemWriter>, io::IoError>
->(value: &T) -> Result<String, Vec<u8>> {
+>(value: &T) -> Result<string::String, Vec<u8>> {
     let buf = to_pretty_vec(value);
-    String::from_utf8(buf)
+    string::String::from_utf8(buf)
 }
 
 /*
@@ -1862,9 +1862,9 @@ impl<Iter: Iterator<char>> Parser<Iter> {
         Ok(n)
     }
 
-    fn parse_string(&mut self) -> Result<String, ParserError> {
+    fn parse_string(&mut self) -> Result<string::String, ParserError> {
         let mut escape = false;
-        let mut res = String::new();
+        let mut res = string::String::new();
 
         loop {
             self.bump();
@@ -2260,7 +2260,7 @@ impl<'a> ToJson for &'a str {
     fn to_json(&self) -> Json { String(self.to_string()) }
 }
 
-impl ToJson for String {
+impl ToJson for string::String {
     fn to_json(&self) -> Json { String((*self).clone()) }
 }
 
@@ -2306,7 +2306,7 @@ impl<A:ToJson> ToJson for Vec<A> {
     fn to_json(&self) -> Json { List(self.iter().map(|elt| elt.to_json()).collect()) }
 }
 
-impl<A:ToJson> ToJson for TreeMap<String, A> {
+impl<A:ToJson> ToJson for TreeMap<string::String, A> {
     fn to_json(&self) -> Json {
         let mut d = TreeMap::new();
         for (key, value) in self.iter() {
@@ -2316,7 +2316,7 @@ impl<A:ToJson> ToJson for TreeMap<String, A> {
     }
 }
 
-impl<A:ToJson> ToJson for HashMap<String, A> {
+impl<A:ToJson> ToJson for HashMap<string::String, A> {
     fn to_json(&self) -> Json {
         let mut d = TreeMap::new();
         for (key, value) in self.iter() {