diff --git a/serde/src/de/impls.rs b/serde/src/de/impls.rs
index d00e483d..0d1d8a4f 100644
--- a/serde/src/de/impls.rs
+++ b/serde/src/de/impls.rs
@@ -565,7 +565,7 @@ array_impls! {
 
 macro_rules! tuple_impls {
     () => {};
-    ($($visitor:ident => ($($name:ident),+),)+) => {
+    ($($len:expr => $visitor:ident => ($($name:ident),+),)+) => {
         $(
             pub struct $visitor<$($name,)+> {
                 marker: PhantomData<($($name,)+)>,
@@ -610,7 +610,7 @@ macro_rules! tuple_impls {
                 fn deserialize<D>(deserializer: &mut D) -> Result<($($name,)+), D::Error>
                     where D: Deserializer,
                 {
-                    deserializer.visit_tuple($visitor::new())
+                    deserializer.visit_tuple($len, $visitor::new())
                 }
             }
         )+
@@ -618,18 +618,18 @@ macro_rules! tuple_impls {
 }
 
 tuple_impls! {
-    TupleVisitor1 => (T0),
-    TupleVisitor2 => (T0, T1),
-    TupleVisitor3 => (T0, T1, T2),
-    TupleVisitor4 => (T0, T1, T2, T3),
-    TupleVisitor5 => (T0, T1, T2, T3, T4),
-    TupleVisitor6 => (T0, T1, T2, T3, T4, T5),
-    TupleVisitor7 => (T0, T1, T2, T3, T4, T5, T6),
-    TupleVisitor8 => (T0, T1, T2, T3, T4, T5, T6, T7),
-    TupleVisitor9 => (T0, T1, T2, T3, T4, T5, T6, T7, T8),
-    TupleVisitor10 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9),
-    TupleVisitor11 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10),
-    TupleVisitor12 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11),
+    1 => TupleVisitor1 => (T0),
+    2 => TupleVisitor2 => (T0, T1),
+    3 => TupleVisitor3 => (T0, T1, T2),
+    4 => TupleVisitor4 => (T0, T1, T2, T3),
+    5 => TupleVisitor5 => (T0, T1, T2, T3, T4),
+    6 => TupleVisitor6 => (T0, T1, T2, T3, T4, T5),
+    7 => TupleVisitor7 => (T0, T1, T2, T3, T4, T5, T6),
+    8 => TupleVisitor8 => (T0, T1, T2, T3, T4, T5, T6, T7),
+    9 => TupleVisitor9 => (T0, T1, T2, T3, T4, T5, T6, T7, T8),
+    10 => TupleVisitor10 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9),
+    11 => TupleVisitor11 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10),
+    12 => TupleVisitor12 => (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11),
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -877,6 +877,14 @@ impl<T, E> Deserialize for Result<T, E> where T: Deserialize, E: Deserialize {
                 impl ::de::Visitor for FieldVisitor {
                     type Value = Field;
 
+                    fn visit_usize<E>(&mut self, value: usize) -> Result<Field, E> where E: Error {
+                        match value {
+                            0 => Ok(Field::Ok),
+                            1 => Ok(Field::Err),
+                            _ => Err(Error::unknown_field_error(&value.to_string())),
+                        }
+                    }
+
                     fn visit_str<E>(&mut self, value: &str) -> Result<Field, E> where E: Error {
                         match value {
                             "Ok" => Ok(Field::Ok),
@@ -916,17 +924,19 @@ impl<T, E> Deserialize for Result<T, E> where T: Deserialize, E: Deserialize {
             {
                 match try!(visitor.visit_variant()) {
                     Field::Ok => {
-                        let (value,) = try!(visitor.visit_seq(TupleVisitor1::new()));
+                        let value = try!(visitor.visit_simple());
                         Ok(Ok(value))
                     }
                     Field::Err => {
-                        let (value,) = try!(visitor.visit_seq(TupleVisitor1::new()));
+                        let value = try!(visitor.visit_simple());
                         Ok(Err(value))
                     }
                 }
             }
         }
 
-        deserializer.visit_enum("Result", Visitor(PhantomData))
+        const VARIANTS: &'static [&'static str] = &["Ok", "Err"];
+
+        deserializer.visit_enum("Result", VARIANTS, Visitor(PhantomData))
     }
 }
diff --git a/serde/src/de/mod.rs b/serde/src/de/mod.rs
index 2f3c6a30..0f865920 100644
--- a/serde/src/de/mod.rs
+++ b/serde/src/de/mod.rs
@@ -211,7 +211,9 @@ pub trait Deserializer {
     /// This method hints that the `Deserialize` type is expecting a named unit. This allows
     /// deserializers to a named unit that aren't tagged as a named unit.
     #[inline]
-    fn visit_unit_struct<V>(&mut self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
+    fn visit_unit_struct<V>(&mut self,
+                            _name: &'static str,
+                            visitor: V) -> Result<V::Value, Self::Error>
         where V: Visitor,
     {
         self.visit_unit(visitor)
@@ -220,17 +222,20 @@ pub trait Deserializer {
     /// This method hints that the `Deserialize` type is expecting a tuple struct. This allows
     /// deserializers to parse sequences that aren't tagged as sequences.
     #[inline]
-    fn visit_tuple_struct<V>(&mut self, _name: &str, visitor: V) -> Result<V::Value, Self::Error>
+    fn visit_tuple_struct<V>(&mut self,
+                             _name: &'static str,
+                             len: usize,
+                             visitor: V) -> Result<V::Value, Self::Error>
         where V: Visitor,
     {
-        self.visit_tuple(visitor)
+        self.visit_tuple(len, visitor)
     }
 
     /// This method hints that the `Deserialize` type is expecting a struct. This allows
     /// deserializers to parse sequences that aren't tagged as maps.
     #[inline]
     fn visit_struct<V>(&mut self,
-                       _name: &str,
+                       _name: &'static str,
                        _fields: &'static [&'static str],
                        visitor: V) -> Result<V::Value, Self::Error>
         where V: Visitor,
@@ -241,7 +246,7 @@ pub trait Deserializer {
     /// This method hints that the `Deserialize` type is expecting a tuple value. This allows
     /// deserializers that provide a custom tuple serialization to properly deserialize the type.
     #[inline]
-    fn visit_tuple<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+    fn visit_tuple<V>(&mut self, _len: usize, visitor: V) -> Result<V::Value, Self::Error>
         where V: Visitor,
     {
         self.visit_seq(visitor)
@@ -251,7 +256,10 @@ pub trait Deserializer {
     /// deserializers that provide a custom enumeration serialization to properly deserialize the
     /// type.
     #[inline]
-    fn visit_enum<V>(&mut self, _enum: &str, _visitor: V) -> Result<V::Value, Self::Error>
+    fn visit_enum<V>(&mut self,
+                     _enum: &'static str,
+                     _variants: &'static [&'static str],
+                     _visitor: V) -> Result<V::Value, Self::Error>
         where V: EnumVisitor,
     {
         Err(Error::syntax_error())
@@ -389,7 +397,7 @@ pub trait Visitor {
     }
 
     #[inline]
-    fn visit_unit_struct<E>(&mut self, _name: &str) -> Result<Self::Value, E>
+    fn visit_unit_struct<E>(&mut self, _name: &'static str) -> Result<Self::Value, E>
         where E: Error,
     {
         self.visit_unit()
@@ -572,21 +580,25 @@ pub trait VariantVisitor {
     }
 
     /// `visit_simple` is called when deserializing a variant with a single value.
-    fn visit_simple<T: Deserialize>(&mut self) -> Result<T, Self::Error> {
+    fn visit_simple<T>(&mut self) -> Result<T, Self::Error>
+        where T: Deserialize,
+    {
         Err(Error::syntax_error())
     }
 
-    /// `visit_seq` is called when deserializing a tuple-like variant.
-    fn visit_seq<V>(&mut self, _visitor: V) -> Result<V::Value, Self::Error>
+    /// `visit_tuple` is called when deserializing a tuple-like variant.
+    fn visit_tuple<V>(&mut self,
+                      _len: usize,
+                      _visitor: V) -> Result<V::Value, Self::Error>
         where V: Visitor
     {
         Err(Error::syntax_error())
     }
 
-    /// `visit_map` is called when deserializing a struct-like variant.
-    fn visit_map<V>(&mut self,
-                    _fields: &'static [&'static str],
-                    _visitor: V) -> Result<V::Value, Self::Error>
+    /// `visit_struct` is called when deserializing a struct-like variant.
+    fn visit_struct<V>(&mut self,
+                       _fields: &'static [&'static str],
+                       _visitor: V) -> Result<V::Value, Self::Error>
         where V: Visitor
     {
         Err(Error::syntax_error())
@@ -606,22 +618,26 @@ impl<'a, T> VariantVisitor for &'a mut T where T: VariantVisitor {
         (**self).visit_unit()
     }
 
-    fn visit_simple<D: Deserialize>(&mut self) -> Result<D, T::Error> {
+    fn visit_simple<D>(&mut self) -> Result<D, T::Error>
+        where D: Deserialize,
+    {
         (**self).visit_simple()
     }
 
-    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, T::Error>
+    fn visit_tuple<V>(&mut self,
+                      len: usize,
+                      visitor: V) -> Result<V::Value, T::Error>
         where V: Visitor,
     {
-        (**self).visit_seq(visitor)
+        (**self).visit_tuple(len, visitor)
     }
 
-    fn visit_map<V>(&mut self,
+    fn visit_struct<V>(&mut self,
                     fields: &'static [&'static str],
                     visitor: V) -> Result<V::Value, T::Error>
         where V: Visitor,
     {
-        (**self).visit_map(fields, visitor)
+        (**self).visit_struct(fields, visitor)
     }
 }
 
diff --git a/serde/src/de/value.rs b/serde/src/de/value.rs
index e512badc..8ad281b7 100644
--- a/serde/src/de/value.rs
+++ b/serde/src/de/value.rs
@@ -136,7 +136,10 @@ impl<'a> de::Deserializer for StrDeserializer<'a> {
         }
     }
 
-    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_enum<V>(&mut self,
+                     _name: &str,
+                     _variants: &'static [&'static str],
+                     mut visitor: V) -> Result<V::Value, Error>
         where V: de::EnumVisitor,
     {
         visitor.visit(self)
@@ -182,7 +185,10 @@ impl de::Deserializer for StringDeserializer {
         }
     }
 
-    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_enum<V>(&mut self,
+                     _name: &str,
+                     _variants: &'static [&'static str],
+                     mut visitor: V) -> Result<V::Value, Error>
         where V: de::EnumVisitor,
     {
         visitor.visit(self)
diff --git a/serde/src/ser/impls.rs b/serde/src/ser/impls.rs
index a8efe18a..ec7c3884 100644
--- a/serde/src/ser/impls.rs
+++ b/serde/src/ser/impls.rs
@@ -97,6 +97,26 @@ impl<T> Serialize for Option<T> where T: Serialize {
     }
 }
 
+impl<T> SeqVisitor for Option<T> where T: Serialize {
+    #[inline]
+    fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
+        where S: Serializer,
+    {
+        match self.take() {
+            Some(value) => {
+                try!(serializer.visit_seq_elt(value));
+                Ok(Some(()))
+            }
+            None => Ok(None),
+        }
+    }
+
+    #[inline]
+    fn len(&self) -> Option<usize> {
+        Some(if self.is_some() { 1 } else { 0 })
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 pub struct SeqIteratorVisitor<Iter> {
@@ -126,8 +146,8 @@ impl<T, Iter> SeqVisitor for SeqIteratorVisitor<Iter>
     {
         match self.iter.next() {
             Some(value) => {
-                let value = try!(serializer.visit_seq_elt(value));
-                Ok(Some(value))
+                try!(serializer.visit_seq_elt(value));
+                Ok(Some(()))
             }
             None => Ok(None),
         }
@@ -612,47 +632,10 @@ impl<T, E> Serialize for Result<T, E> where T: Serialize, E: Serialize {
     fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: Serializer {
         match *self {
             Result::Ok(ref value) => {
-                struct Visitor<'a, T: 'a>(Option<&'a T>);
-
-                impl<'a, T> SeqVisitor for Visitor<'a, T> where T: Serialize + 'a {
-                    #[inline]
-                    fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
-                        where S: Serializer
-                    {
-                        match self.0.take() {
-                            Some(value) => Ok(Some(try!(serializer.visit_seq_elt(value)))),
-                            None => Ok(None),
-                        }
-                    }
-
-                    #[inline]
-                    fn len(&self) -> Option<usize> {
-                        Some(1)
-                    }
-                }
-
-                serializer.visit_enum_seq("Result", 0, "Ok", Visitor(Some(value)))
+                serializer.visit_enum_simple("Result", 0, "Ok", value)
             }
             Result::Err(ref value) => {
-                struct Visitor<'a, E: 'a>(Option<&'a E>);
-
-                impl<'a, E> SeqVisitor for Visitor<'a, E> where E: Serialize + 'a {
-                    #[inline]
-                    fn visit<S>(&mut self, serializer: &mut S) -> Result<Option<()>, S::Error>
-                                where S: Serializer {
-                        match self.0.take() {
-                            Some(value) => Ok(Some(try!(serializer.visit_seq_elt(value)))),
-                            None => Ok(None),
-                        }
-                    }
-
-                    #[inline]
-                    fn len(&self) -> Option<usize> {
-                        Some(1)
-                    }
-                }
-
-                serializer.visit_enum_seq("Result", 1, "Err", Visitor(Some(value)))
+                serializer.visit_enum_simple("Result", 1, "Err", value)
             }
         }
     }
diff --git a/serde/src/ser/mod.rs b/serde/src/ser/mod.rs
index 4484d344..816e932a 100644
--- a/serde/src/ser/mod.rs
+++ b/serde/src/ser/mod.rs
@@ -113,25 +113,32 @@ pub trait Serializer {
     fn visit_unit(&mut self) -> Result<(), Self::Error>;
 
     #[inline]
-    fn visit_unit_struct(&mut self, _name: &str) -> Result<(), Self::Error> {
+    fn visit_unit_struct(&mut self, _name: &'static str) -> Result<(), Self::Error> {
         self.visit_unit()
     }
 
     #[inline]
-    fn visit_enum_unit(&mut self,
-                       _name: &str,
-                       _variant_index: usize,
-                       _variant: &str) -> Result<(), Self::Error> {
+    fn visit_unit_variant(&mut self,
+                          _name: &'static str,
+                          _variant_index: usize,
+                          _variant: &'static str) -> Result<(), Self::Error> {
         self.visit_unit()
     }
 
     #[inline]
     fn visit_enum_simple<T>(&mut self,
-                            _name: &str,
-                            _variant: &str,
-                            _value: T,
-                            ) -> Result<(), Self::Error>
-        where T: Serialize;
+                            name: &'static str,
+                            variant_index: usize,
+                            variant: &'static str,
+                            value: T) -> Result<(), Self::Error>
+        where T: Serialize,
+    {
+        self.visit_tuple_variant(
+            name,
+            variant_index,
+            variant,
+            Some(value))
+    }
 
     fn visit_none(&mut self) -> Result<(), Self::Error>;
 
@@ -160,8 +167,8 @@ pub trait Serializer {
 
     #[inline]
     fn visit_tuple_struct<V>(&mut self,
-                          _name: &'static str,
-                          visitor: V) -> Result<(), Self::Error>
+                             _name: &'static str,
+                             visitor: V) -> Result<(), Self::Error>
         where V: SeqVisitor,
     {
         self.visit_tuple(visitor)
@@ -175,18 +182,18 @@ pub trait Serializer {
     }
 
     #[inline]
-    fn visit_enum_seq<V>(&mut self,
-                         _name: &'static str,
-                         _variant_index: usize,
-                         variant: &'static str,
-                         visitor: V) -> Result<(), Self::Error>
+    fn visit_tuple_variant<V>(&mut self,
+                              _name: &'static str,
+                              _variant_index: usize,
+                              variant: &'static str,
+                              visitor: V) -> Result<(), Self::Error>
         where V: SeqVisitor,
     {
         self.visit_tuple_struct(variant, visitor)
     }
 
     #[inline]
-    fn visit_enum_seq_elt<T>(&mut self, value: T) -> Result<(), Self::Error>
+    fn visit_tuple_variant_elt<T>(&mut self, value: T) -> Result<(), Self::Error>
         where T: Serialize
     {
         self.visit_tuple_struct_elt(value)
@@ -201,15 +208,17 @@ pub trait Serializer {
 
     #[inline]
     fn visit_struct<V>(&mut self,
-                          _name: &'static str,
-                          visitor: V) -> Result<(), Self::Error>
+                       _name: &'static str,
+                       visitor: V) -> Result<(), Self::Error>
         where V: MapVisitor,
     {
         self.visit_map(visitor)
     }
 
     #[inline]
-    fn visit_struct_elt<K, V>(&mut self, key: K, value: V) -> Result<(), Self::Error>
+    fn visit_struct_elt<K, V>(&mut self,
+                              key: K,
+                              value: V) -> Result<(), Self::Error>
         where K: Serialize,
               V: Serialize,
     {
@@ -217,18 +226,20 @@ pub trait Serializer {
     }
 
     #[inline]
-    fn visit_enum_map<V>(&mut self,
-                         _name: &'static str,
-                         _variant_index: usize,
-                         variant: &'static str,
-                         visitor: V) -> Result<(), Self::Error>
+    fn visit_struct_variant<V>(&mut self,
+                               _name: &'static str,
+                               _variant_index: usize,
+                               variant: &'static str,
+                               visitor: V) -> Result<(), Self::Error>
         where V: MapVisitor,
     {
         self.visit_struct(variant, visitor)
     }
 
     #[inline]
-    fn visit_enum_map_elt<K, V>(&mut self, key: K, value: V) -> Result<(), Self::Error>
+    fn visit_struct_variant_elt<K, V>(&mut self,
+                                      key: K,
+                                      value: V) -> Result<(), Self::Error>
         where K: Serialize,
               V: Serialize,
     {
diff --git a/serde_codegen/src/de.rs b/serde_codegen/src/de.rs
index 8fb69f0e..a34d44d6 100644
--- a/serde_codegen/src/de.rs
+++ b/serde_codegen/src/de.rs
@@ -318,7 +318,7 @@ fn deserialize_tuple_struct(
             }
         }
 
-        deserializer.visit_tuple_struct($type_name, $visitor_expr)
+        deserializer.visit_tuple_struct($type_name, $fields, $visitor_expr)
     })
 }
 
@@ -489,6 +489,19 @@ fn deserialize_item_enum(
             .collect()
     );
 
+    let variants_expr = builder.expr().addr_of().slice()
+        .with_exprs(
+            enum_def.variants.iter()
+                .map(|variant| {
+                    builder.expr().str(variant.node.name)
+                })
+        )
+        .build();
+
+    let variants_stmt = quote_stmt!(cx,
+        const VARIANTS: &'static [&'static str] = $variants_expr;
+    ).unwrap();
+
     // Match arms to extract a variant from a string
     let variant_arms: Vec<_> = enum_def.variants.iter()
         .enumerate()
@@ -535,7 +548,9 @@ fn deserialize_item_enum(
             }
         }
 
-        deserializer.visit_enum($type_name, $visitor_expr)
+        $variants_stmt
+
+        deserializer.visit_enum($type_name, VARIANTS, $visitor_expr)
     })
 }
 
@@ -626,7 +641,7 @@ fn deserialize_tuple_variant(
             }
         }
 
-        visitor.visit_seq($visitor_expr)
+        visitor.visit_tuple($fields, $visitor_expr)
     })
 }
 
@@ -693,7 +708,7 @@ fn deserialize_struct_variant(
 
         $fields_stmt
 
-        visitor.visit_map(FIELDS, $visitor_expr)
+        visitor.visit_struct(FIELDS, $visitor_expr)
     })
 }
 
@@ -750,10 +765,10 @@ fn deserialize_field_visitor(
     let str_body = if formats.is_empty() {
         // No formats specific attributes, so no match on format required
         quote_expr!(cx,
-                    match value {
-                        $default_field_arms
-                        _ => { Err(::serde::de::Error::unknown_field_error(value)) }
-                    })
+            match value {
+                $default_field_arms
+                _ => { Err(::serde::de::Error::unknown_field_error(value)) }
+            })
     } else {
         let field_arms: Vec<_> = formats.iter()
             .map(|fmt| {
diff --git a/serde_codegen/src/ser.rs b/serde_codegen/src/ser.rs
index b4e4f7f4..7d80f9dd 100644
--- a/serde_codegen/src/ser.rs
+++ b/serde_codegen/src/ser.rs
@@ -288,7 +288,7 @@ fn serialize_variant(
 
             quote_arm!(cx,
                 $pat => {
-                    ::serde::ser::Serializer::visit_enum_unit(
+                    ::serde::ser::Serializer::visit_unit_variant(
                         serializer,
                         $type_name,
                         $variant_index,
@@ -309,6 +309,7 @@ fn serialize_variant(
                     ::serde::ser::Serializer::visit_enum_simple(
                         serializer,
                         $type_name,
+                        $variant_index,
                         $variant_name,
                         __simple_value,
                     )
@@ -421,7 +422,7 @@ fn serialize_tuple_variant(
     quote_expr!(cx, {
         $visitor_struct
         $visitor_impl
-        serializer.visit_enum_seq($type_name, $variant_index, $variant_name, Visitor {
+        serializer.visit_tuple_variant($type_name, $variant_index, $variant_name, Visitor {
             value: $value_expr,
             state: 0,
             _structure_ty: ::std::marker::PhantomData::<&$structure_ty>,
@@ -476,7 +477,7 @@ fn serialize_struct_variant(
     quote_expr!(cx, {
         $visitor_struct
         $visitor_impl
-        serializer.visit_enum_map($type_name, $variant_index, $variant_name, Visitor {
+        serializer.visit_struct_variant($type_name, $variant_index, $variant_name, Visitor {
             value: $value_expr,
             state: 0,
             _structure_ty: ::std::marker::PhantomData::<&$structure_ty>,
diff --git a/serde_json/src/de.rs b/serde_json/src/de.rs
index efdd53df..5fbbfb1c 100644
--- a/serde_json/src/de.rs
+++ b/serde_json/src/de.rs
@@ -454,7 +454,10 @@ impl<Iter> de::Deserializer for Deserializer<Iter>
     }
 
     #[inline]
-    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_enum<V>(&mut self,
+                     _name: &str,
+                     _variants: &'static [&'static str],
+                     mut visitor: V) -> Result<V::Value, Error>
         where V: de::EnumVisitor,
     {
         try!(self.parse_whitespace());
@@ -645,15 +648,17 @@ impl<Iter> de::VariantVisitor for Deserializer<Iter>
         de::Deserialize::deserialize(self)
     }
 
-    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+    fn visit_tuple<V>(&mut self,
+                      _len: usize,
+                      visitor: V) -> Result<V::Value, Error>
         where V: de::Visitor,
     {
         de::Deserializer::visit(self, visitor)
     }
 
-    fn visit_map<V>(&mut self,
-                    _fields: &'static [&'static str],
-                    visitor: V) -> Result<V::Value, Error>
+    fn visit_struct<V>(&mut self,
+                       _fields: &'static [&'static str],
+                       visitor: V) -> Result<V::Value, Error>
         where V: de::Visitor,
     {
         de::Deserializer::visit(self, visitor)
diff --git a/serde_json/src/ser.rs b/serde_json/src/ser.rs
index b7f5b2d8..c1368833 100644
--- a/serde_json/src/ser.rs
+++ b/serde_json/src/ser.rs
@@ -159,10 +159,10 @@ impl<W, F> ser::Serializer for Serializer<W, F>
     }
 
     #[inline]
-    fn visit_enum_unit(&mut self,
-                       _name: &str,
-                       _variant_index: usize,
-                       variant: &str) -> io::Result<()> {
+    fn visit_unit_variant(&mut self,
+                          _name: &str,
+                          _variant_index: usize,
+                          variant: &str) -> io::Result<()> {
         try!(self.formatter.open(&mut self.writer, b'{'));
         try!(self.formatter.comma(&mut self.writer, true));
         try!(self.visit_str(variant));
@@ -174,6 +174,7 @@ impl<W, F> ser::Serializer for Serializer<W, F>
     #[inline]
     fn visit_enum_simple<T>(&mut self,
                             _name: &str,
+                            _variant_index: usize,
                             variant: &str,
                             value: T,
                             ) -> io::Result<()>
@@ -209,11 +210,11 @@ impl<W, F> ser::Serializer for Serializer<W, F>
     }
 
     #[inline]
-    fn visit_enum_seq<V>(&mut self,
-                         _name: &str,
-                         _variant_index: usize,
-                         variant: &str,
-                         visitor: V) -> io::Result<()>
+    fn visit_tuple_variant<V>(&mut self,
+                              _name: &str,
+                              _variant_index: usize,
+                              variant: &str,
+                              visitor: V) -> io::Result<()>
         where V: ser::SeqVisitor,
     {
         try!(self.formatter.open(&mut self.writer, b'{'));
@@ -257,11 +258,11 @@ impl<W, F> ser::Serializer for Serializer<W, F>
     }
 
     #[inline]
-    fn visit_enum_map<V>(&mut self,
-                         _name: &str,
-                         _variant_index: usize,
-                         variant: &str,
-                         visitor: V) -> io::Result<()>
+    fn visit_struct_variant<V>(&mut self,
+                               _name: &str,
+                               _variant_index: usize,
+                               variant: &str,
+                               visitor: V) -> io::Result<()>
         where V: ser::MapVisitor,
     {
         try!(self.formatter.open(&mut self.writer, b'{'));
diff --git a/serde_json/src/value.rs b/serde_json/src/value.rs
index f01dfe1d..ea40cb83 100644
--- a/serde_json/src/value.rs
+++ b/serde_json/src/value.rs
@@ -459,10 +459,10 @@ impl ser::Serializer for Serializer {
     }
 
     #[inline]
-    fn visit_enum_unit(&mut self,
-                       _name: &str,
-                       _variant_index: usize,
-                       variant: &str) -> Result<(), ()> {
+    fn visit_unit_variant(&mut self,
+                          _name: &str,
+                          _variant_index: usize,
+                          variant: &str) -> Result<(), ()> {
         let mut values = BTreeMap::new();
         values.insert(variant.to_string(), Value::Array(vec![]));
 
@@ -474,6 +474,7 @@ impl ser::Serializer for Serializer {
     #[inline]
     fn visit_enum_simple<T>(&mut self,
                             _name: &str,
+                            _variant_index: usize,
                             variant: &str,
                             value: T,
                             ) -> Result<(), ()>
@@ -509,11 +510,11 @@ impl ser::Serializer for Serializer {
     }
 
     #[inline]
-    fn visit_enum_seq<V>(&mut self,
-                         _name: &str,
-                         _variant_index: usize,
-                         variant: &str,
-                         visitor: V) -> Result<(), ()>
+    fn visit_tuple_variant<V>(&mut self,
+                              _name: &str,
+                              _variant_index: usize,
+                              variant: &str,
+                              visitor: V) -> Result<(), ()>
         where V: ser::SeqVisitor,
     {
         try!(self.visit_seq(visitor));
@@ -572,11 +573,11 @@ impl ser::Serializer for Serializer {
     }
 
     #[inline]
-    fn visit_enum_map<V>(&mut self,
-                         _name: &str,
-                         _variant_index: usize,
-                         variant: &str,
-                         visitor: V) -> Result<(), ()>
+    fn visit_struct_variant<V>(&mut self,
+                               _name: &str,
+                               _variant_index: usize,
+                               variant: &str,
+                               visitor: V) -> Result<(), ()>
         where V: ser::MapVisitor,
     {
         try!(self.visit_map(visitor));
@@ -692,7 +693,10 @@ impl de::Deserializer for Deserializer {
     }
 
     #[inline]
-    fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_enum<V>(&mut self,
+                     _name: &str,
+                     _variants: &'static [&'static str],
+                     mut visitor: V) -> Result<V::Value, Error>
         where V: de::EnumVisitor,
     {
         let value = match self.value.take() {
@@ -740,17 +744,19 @@ impl<'a> de::VariantVisitor for VariantDeserializer<'a> {
         de::Deserialize::deserialize(&mut Deserializer::new(self.variant.take().unwrap()))
     }
 
-    fn visit_unit(&mut self) -> Result<(), Error>
+    fn visit_unit(&mut self) -> Result<(), Error> {
+        de::Deserialize::deserialize(&mut Deserializer::new(self.val.take().unwrap()))
+    }
+
+    fn visit_simple<T>(&mut self) -> Result<T, Error>
+        where T: de::Deserialize,
     {
         de::Deserialize::deserialize(&mut Deserializer::new(self.val.take().unwrap()))
     }
 
-    fn visit_simple<D: de::Deserialize>(&mut self) -> Result<D, Error>
-    {
-        de::Deserialize::deserialize(&mut Deserializer::new(self.val.take().unwrap()))
-    }
-
-    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, Error>
+    fn visit_tuple<V>(&mut self,
+                      _len: usize,
+                      visitor: V) -> Result<V::Value, Error>
         where V: de::Visitor,
     {
         if let Value::Array(fields) = self.val.take().unwrap() {
@@ -767,7 +773,9 @@ impl<'a> de::VariantVisitor for VariantDeserializer<'a> {
         }
     }
 
-    fn visit_map<V>(&mut self, _fields: &'static[&'static str], visitor: V) -> Result<V::Value, Error>
+    fn visit_struct<V>(&mut self,
+                       _fields: &'static[&'static str],
+                       visitor: V) -> Result<V::Value, Error>
         where V: de::Visitor,
     {
         if let Value::Object(fields) = self.val.take().unwrap() {
diff --git a/serde_tests/benches/bench_enum.rs b/serde_tests/benches/bench_enum.rs
index 2b83507b..b97c20cc 100644
--- a/serde_tests/benches/bench_enum.rs
+++ b/serde_tests/benches/bench_enum.rs
@@ -288,7 +288,10 @@ mod deserializer {
         }
 
         #[inline]
-        fn visit_enum<V>(&mut self, _name: &str, mut visitor: V) -> Result<V::Value, Error>
+        fn visit_enum<V>(&mut self,
+                         _name: &str,
+                         _variants: &[&str],
+                         mut visitor: V) -> Result<V::Value, Error>
             where V: de::EnumVisitor,
         {
             match self.stack.pop() {
@@ -350,7 +353,9 @@ mod deserializer {
             de::Deserialize::deserialize(self.de)
         }
 
-        fn visit_seq<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
+        fn visit_tuple<V>(&mut self,
+                          _len: usize,
+                          mut visitor: V) -> Result<V::Value, Error>
             where V: de::Visitor,
         {
             visitor.visit_seq(self)
diff --git a/serde_tests/tests/test_bytes.rs b/serde_tests/tests/test_bytes.rs
index 65c466a3..3ca97285 100644
--- a/serde_tests/tests/test_bytes.rs
+++ b/serde_tests/tests/test_bytes.rs
@@ -39,15 +39,6 @@ impl serde::Serializer for BytesSerializer {
         Err(Error)
     }
 
-    fn visit_enum_simple<T>(&mut self,
-                            _name: &str,
-                            _variant: &str,
-                            _value: T,
-                            ) -> Result<(), Error>
-    {
-        Err(Error)
-    }
-
     fn visit_bool(&mut self, _v: bool) -> Result<(), Error> {
         Err(Error)
     }
diff --git a/serde_tests/tests/test_de.rs b/serde_tests/tests/test_de.rs
index 9b789c84..2783654c 100644
--- a/serde_tests/tests/test_de.rs
+++ b/serde_tests/tests/test_de.rs
@@ -22,6 +22,7 @@ enum Token {
     Char(char),
     Str(&'static str),
     String(String),
+    Bytes(&'static [u8]),
 
     Option(bool),
 
@@ -38,6 +39,10 @@ enum Token {
     MapEnd,
 
     EnumStart(&'static str),
+    EnumUnit,
+    EnumSimple,
+    EnumSeq,
+    EnumMap,
     EnumEnd,
 }
 
@@ -99,6 +104,7 @@ impl Deserializer for TokenDeserializer {
             Some(Token::Char(v)) => visitor.visit_char(v),
             Some(Token::Str(v)) => visitor.visit_str(v),
             Some(Token::String(v)) => visitor.visit_string(v),
+            Some(Token::Bytes(v)) => visitor.visit_bytes(v),
             Some(Token::Option(false)) => visitor.visit_none(),
             Some(Token::Option(true)) => visitor.visit_some(self),
             Some(Token::Unit) => visitor.visit_unit(),
@@ -143,7 +149,10 @@ impl Deserializer for TokenDeserializer {
         }
     }
 
-    fn visit_enum<V>(&mut self, name: &str, mut visitor: V) -> Result<V::Value, Error>
+    fn visit_enum<V>(&mut self,
+                     name: &str,
+                     _variants: &'static [&'static str],
+                     mut visitor: V) -> Result<V::Value, Error>
         where V: de::EnumVisitor,
     {
         match self.tokens.next() {
@@ -178,7 +187,10 @@ impl Deserializer for TokenDeserializer {
         }
     }
 
-    fn visit_tuple_struct<V>(&mut self, name: &str, visitor: V) -> Result<V::Value, Error>
+    fn visit_tuple_struct<V>(&mut self,
+                             name: &str,
+                             _len: usize,
+                             visitor: V) -> Result<V::Value, Error>
         where V: de::Visitor,
     {
         match self.tokens.peek() {
@@ -318,21 +330,53 @@ impl<'a> de::VariantVisitor for TokenDeserializerVariantVisitor<'a> {
     }
 
     fn visit_unit(&mut self) -> Result<(), Error> {
-        de::Deserialize::deserialize(self.de)
+        match self.de.tokens.next() {
+            Some(Token::EnumUnit) => {
+                de::Deserialize::deserialize(self.de)
+            }
+            Some(_) => Err(Error::SyntaxError),
+            None => Err(Error::EndOfStreamError),
+        }
     }
 
-    fn visit_seq<V>(&mut self, visitor: V) -> Result<V::Value, Error>
-        where V: de::Visitor,
+    fn visit_simple<T>(&mut self) -> Result<T, Self::Error>
+        where T: de::Deserialize,
     {
-        de::Deserializer::visit(self.de, visitor)
+        match self.de.tokens.next() {
+            Some(Token::EnumSimple) => {
+                de::Deserialize::deserialize(self.de)
+            }
+            Some(_) => Err(Error::SyntaxError),
+            None => Err(Error::EndOfStreamError),
+        }
     }
 
-    fn visit_map<V>(&mut self,
-                    _fields: &'static [&'static str],
-                    visitor: V) -> Result<V::Value, Error>
+    fn visit_tuple<V>(&mut self,
+                      _len: usize,
+                      visitor: V) -> Result<V::Value, Error>
         where V: de::Visitor,
     {
-        de::Deserializer::visit(self.de, visitor)
+        match self.de.tokens.next() {
+            Some(Token::EnumSeq) => {
+                de::Deserializer::visit(self.de, visitor)
+            }
+            Some(_) => Err(Error::SyntaxError),
+            None => Err(Error::EndOfStreamError),
+        }
+    }
+
+    fn visit_struct<V>(&mut self,
+                       _fields: &'static [&'static str],
+                       visitor: V) -> Result<V::Value, Error>
+        where V: de::Visitor,
+    {
+        match self.de.tokens.next() {
+            Some(Token::EnumMap) => {
+                de::Deserializer::visit(self.de, visitor)
+            }
+            Some(_) => Err(Error::SyntaxError),
+            None => Err(Error::EndOfStreamError),
+        }
     }
 }
 
@@ -354,6 +398,7 @@ struct Struct {
 #[derive(PartialEq, Debug, Deserialize)]
 enum Enum {
     Unit,
+    Simple(i32),
     Seq(i32, i32, i32),
     Map { a: i32, b: i32, c: i32 }
 }
@@ -495,20 +540,18 @@ declare_tests! {
         Ok::<i32, i32>(0) => vec![
             Token::EnumStart("Result"),
                 Token::Str("Ok"),
-                Token::SeqStart(1),
-                    Token::SeqSep,
-                    Token::I32(0),
-                Token::SeqEnd,
-            Token::EnumEnd,
+
+                Token::EnumSimple,
+                Token::I32(0),
+            Token::SeqEnd,
         ],
         Err::<i32, i32>(1) => vec![
             Token::EnumStart("Result"),
                 Token::Str("Err"),
-                Token::SeqStart(1),
-                    Token::SeqSep,
-                    Token::I32(1),
-                Token::SeqEnd,
-            Token::EnumEnd,
+
+                Token::EnumSimple,
+                Token::I32(1),
+            Token::SeqEnd,
         ],
     }
     test_unit {
@@ -880,14 +923,28 @@ declare_tests! {
         Enum::Unit => vec![
             Token::EnumStart("Enum"),
                 Token::Str("Unit"),
+
+                Token::EnumUnit,
                 Token::Unit,
             Token::EnumEnd,
         ],
     }
+    test_enum_simple {
+        Enum::Simple(1) => vec![
+            Token::EnumStart("Enum"),
+                Token::Str("Simple"),
+
+                Token::EnumSimple,
+                Token::I32(1),
+            Token::EnumEnd,
+        ],
+    }
     test_enum_seq {
         Enum::Seq(1, 2, 3) => vec![
             Token::EnumStart("Enum"),
                 Token::Str("Seq"),
+
+                Token::EnumSeq,
                 Token::SeqStart(3),
                     Token::SeqSep,
                     Token::I32(1),
@@ -905,6 +962,8 @@ declare_tests! {
         Enum::Map { a: 1, b: 2, c: 3 } => vec![
             Token::EnumStart("Enum"),
                 Token::Str("Map"),
+
+                Token::EnumMap,
                 Token::MapStart(3),
                     Token::MapSep,
                     Token::Str("a"),
@@ -921,4 +980,24 @@ declare_tests! {
             Token::EnumEnd,
         ],
     }
+    test_enum_unit_usize {
+        Enum::Unit => vec![
+            Token::EnumStart("Enum"),
+                Token::Usize(0),
+
+                Token::EnumUnit,
+                Token::Unit,
+            Token::EnumEnd,
+        ],
+    }
+    test_enum_unit_bytes {
+        Enum::Unit => vec![
+            Token::EnumStart("Enum"),
+                Token::Bytes(b"Unit"),
+
+                Token::EnumUnit,
+                Token::Unit,
+            Token::EnumEnd,
+        ],
+    }
 }
diff --git a/serde_tests/tests/test_ser.rs b/serde_tests/tests/test_ser.rs
index 62627fba..6b0d8347 100644
--- a/serde_tests/tests/test_ser.rs
+++ b/serde_tests/tests/test_ser.rs
@@ -84,6 +84,7 @@ impl<'a> Serializer for AssertSerializer<'a> {
 
     fn visit_enum_simple<T>(&mut self,
                             name: &str,
+                            _variant_index: usize,
                             variant: &str,
                             value: T,
                             ) -> Result<(), ()>
@@ -98,10 +99,10 @@ impl<'a> Serializer for AssertSerializer<'a> {
         Ok(())
     }
 
-    fn visit_enum_unit(&mut self,
-                       name: &str,
-                       _variant_index: usize,
-                       variant: &str) -> Result<(), ()> {
+    fn visit_unit_variant(&mut self,
+                          name: &str,
+                          _variant_index: usize,
+                          variant: &str) -> Result<(), ()> {
         assert_eq!(
             self.iter.next().unwrap(),
             Token::EnumUnit(name, variant)
@@ -221,11 +222,11 @@ impl<'a> Serializer for AssertSerializer<'a> {
         self.visit_sequence(visitor)
     }
 
-    fn visit_enum_seq<V>(&mut self,
-                         name: &str,
-                         _variant_index: usize,
-                         variant: &str,
-                         visitor: V) -> Result<(), ()>
+    fn visit_tuple_variant<V>(&mut self,
+                              name: &str,
+                              _variant_index: usize,
+                              variant: &str,
+                              visitor: V) -> Result<(), ()>
         where V: SeqVisitor
     {
         let len = visitor.len();
@@ -268,11 +269,11 @@ impl<'a> Serializer for AssertSerializer<'a> {
         self.visit_mapping(visitor)
     }
 
-    fn visit_enum_map<V>(&mut self,
-                         name: &str,
-                         _variant_index: usize,
-                         variant: &str,
-                         visitor: V) -> Result<(), ()>
+    fn visit_struct_variant<V>(&mut self,
+                               name: &str,
+                               _variant_index: usize,
+                               variant: &str,
+                               visitor: V) -> Result<(), ()>
         where V: MapVisitor
     {
         let len = visitor.len();
@@ -396,16 +397,12 @@ declare_tests! {
     }
     test_result {
         Ok::<i32, i32>(0) => vec![
-            Token::EnumSeqStart("Result", "Ok", Some(1)),
-            Token::SeqSep,
+            Token::EnumSimple("Result", "Ok"),
             Token::I32(0),
-            Token::SeqEnd,
         ],
         Err::<i32, i32>(1) => vec![
-            Token::EnumSeqStart("Result", "Err", Some(1)),
-            Token::SeqSep,
+            Token::EnumSimple("Result", "Err"),
             Token::I32(1),
-            Token::SeqEnd,
         ],
     }
     test_slice {