diff --git a/src/decoder/mod.rs b/src/decoder/mod.rs
index 9720528..51a9ea2 100644
--- a/src/decoder/mod.rs
+++ b/src/decoder/mod.rs
@@ -1,9 +1,7 @@
 use std::error;
 use std::fmt;
 
-#[cfg(feature = "rustc-serialize")]
 use std::collections::{btree_map, BTreeMap};
-#[cfg(feature = "rustc-serialize")]
 use std::iter::Peekable;
 
 use Value;
@@ -22,9 +20,11 @@ pub struct Decoder {
     /// whether fields were decoded or not.
     pub toml: Option<Value>,
     cur_field: Option<String>,
-    #[cfg(feature = "rustc-serialize")]
+
+    // These aren't used if serde is in use
+    #[cfg_attr(feature = "serde", allow(dead_code))]
     cur_map: Peekable<btree_map::IntoIter<String, Value>>,
-    #[cfg(feature = "rustc-serialize")]
+    #[cfg_attr(feature = "serde", allow(dead_code))]
     leftover_map: ::Table,
 }
 
@@ -135,7 +135,6 @@ impl Decoder {
         Decoder::new_empty(toml, cur_field)
     }
 
-    #[cfg(feature = "rustc-serialize")]
     fn new_empty(toml: Option<Value>, cur_field: Option<String>) -> Decoder {
         Decoder {
             toml: toml,
@@ -145,14 +144,6 @@ impl Decoder {
         }
     }
 
-    #[cfg(not(feature = "rustc-serialize"))]
-    fn new_empty(toml: Option<Value>, cur_field: Option<String>) -> Decoder {
-        Decoder {
-            toml: toml,
-            cur_field: cur_field,
-        }
-    }
-
     fn err(&self, kind: DecodeErrorKind) -> DecodeError {
         DecodeError {
             field: self.cur_field.clone(),
diff --git a/src/encoder/mod.rs b/src/encoder/mod.rs
index fb00a47..d3aba1b 100644
--- a/src/encoder/mod.rs
+++ b/src/encoder/mod.rs
@@ -66,9 +66,14 @@ pub enum Error {
     Custom(String),
 }
 
+/// Internal state of the encoder when encoding transitions
+#[derive(Debug)]
+pub struct EncoderState {
+    inner: State,
+}
+
 #[derive(PartialEq, Debug)]
-#[doc(hidden)]
-pub enum State {
+enum State {
     Start,
     NextKey(String),
     NextArray(Vec<Value>),
@@ -113,15 +118,6 @@ impl Encoder {
         }
     }
 
-    #[cfg(feature = "rustc-serialize")]
-    fn seq<F>(&mut self, f: F) -> Result<(), Error>
-        where F: FnOnce(&mut Encoder) -> Result<(), Error>
-    {
-        let old = try!(self.seq_begin());
-        try!(f(self));
-        self.seq_end(old)
-    }
-
     fn seq_begin(&mut self) -> Result<State, Error> {
         Ok(mem::replace(&mut self.state, State::NextArray(Vec::new())))
     }
@@ -133,55 +129,6 @@ impl Encoder {
         }
     }
 
-    #[cfg(feature = "rustc-serialize")]
-    fn table<F>(&mut self, f: F) -> Result<(), Error>
-        where F: FnOnce(&mut Encoder) -> Result<(), Error>
-    {
-        match mem::replace(&mut self.state, State::Start) {
-            State::NextKey(key) => {
-                let mut nested = Encoder::new();
-                try!(f(&mut nested));
-                self.toml.insert(key, Value::Table(nested.toml));
-                Ok(())
-            }
-            State::NextArray(mut arr) => {
-                let mut nested = Encoder::new();
-                try!(f(&mut nested));
-                arr.push(Value::Table(nested.toml));
-                self.state = State::NextArray(arr);
-                Ok(())
-            }
-            State::Start => f(self),
-            State::NextMapKey => Err(Error::InvalidMapKeyLocation),
-        }
-    }
-
-    #[cfg(feature = "serde")]
-    fn table_begin(&mut self) -> Result<Self, Error> {
-        match self.state {
-            State::NextMapKey => Err(Error::InvalidMapKeyLocation),
-            _ => Ok(mem::replace(self, Encoder::new()))
-        }
-    }
-
-    #[cfg(feature = "serde")]
-    fn table_end(&mut self, mut state: Self) -> Result<(), Error> {
-        match state.state {
-            State::NextKey(key) => {
-                mem::swap(&mut self.toml, &mut state.toml);
-                self.toml.insert(key, Value::Table(state.toml));
-            },
-            State::NextArray(mut arr) => {
-                mem::swap(&mut self.toml, &mut state.toml);
-                arr.push(Value::Table(state.toml));
-                self.state = State::NextArray(arr);
-            },
-            State::Start => {},
-            State::NextMapKey => unreachable!(),
-        }
-        Ok(())
-    }
-
     fn table_key<F>(&mut self, f: F) -> Result<(), Error>
         where F: FnOnce(&mut Encoder) -> Result<(), Error>
     {
diff --git a/src/encoder/rustc_serialize.rs b/src/encoder/rustc_serialize.rs
index 6dce66a..0eda740 100644
--- a/src/encoder/rustc_serialize.rs
+++ b/src/encoder/rustc_serialize.rs
@@ -5,6 +5,38 @@ use Value;
 use super::{Encoder, Error, State};
 use super::Error::*;
 
+impl Encoder {
+    fn table<F>(&mut self, f: F) -> Result<(), Error>
+        where F: FnOnce(&mut Encoder) -> Result<(), Error>
+    {
+        match mem::replace(&mut self.state, State::Start) {
+            State::NextKey(key) => {
+                let mut nested = Encoder::new();
+                try!(f(&mut nested));
+                self.toml.insert(key, Value::Table(nested.toml));
+                Ok(())
+            }
+            State::NextArray(mut arr) => {
+                let mut nested = Encoder::new();
+                try!(f(&mut nested));
+                arr.push(Value::Table(nested.toml));
+                self.state = State::NextArray(arr);
+                Ok(())
+            }
+            State::Start => f(self),
+            State::NextMapKey => Err(Error::InvalidMapKeyLocation),
+        }
+    }
+
+    fn seq<F>(&mut self, f: F) -> Result<(), Error>
+        where F: FnOnce(&mut Encoder) -> Result<(), Error>
+    {
+        let old = try!(self.seq_begin());
+        try!(f(self));
+        self.seq_end(old)
+    }
+}
+
 impl rustc_serialize::Encoder for Encoder {
     type Error = Error;
 
diff --git a/src/encoder/serde.rs b/src/encoder/serde.rs
index fcccc3d..997bc37 100644
--- a/src/encoder/serde.rs
+++ b/src/encoder/serde.rs
@@ -1,76 +1,125 @@
+use std::mem;
+
 use serde::ser;
 use Value;
-use super::{Encoder, Error, State};
+use super::{Encoder, Error, EncoderState, State};
+
+impl Encoder {
+    fn table_begin(&mut self) -> Result<Self, Error> {
+        match self.state {
+            State::NextMapKey => Err(Error::InvalidMapKeyLocation),
+            _ => Ok(mem::replace(self, Encoder::new()))
+        }
+    }
+
+    fn table_end(&mut self, mut state: Self) -> Result<(), Error> {
+        match state.state {
+            State::NextKey(key) => {
+                mem::swap(&mut self.toml, &mut state.toml);
+                self.toml.insert(key, Value::Table(state.toml));
+            },
+            State::NextArray(mut arr) => {
+                mem::swap(&mut self.toml, &mut state.toml);
+                arr.push(Value::Table(state.toml));
+                self.state = State::NextArray(arr);
+            },
+            State::Start => {},
+            State::NextMapKey => unreachable!(),
+        }
+        Ok(())
+    }
+}
 
 impl ser::Serializer for Encoder {
     type Error = Error;
     type MapState = Self;
     type StructState = Self;
     type StructVariantState = Self;
-    type SeqState = State;
-    type TupleState = State;
-    type TupleStructState = State;
-    type TupleVariantState = State;
+    type SeqState = EncoderState;
+    type TupleState = EncoderState;
+    type TupleStructState = EncoderState;
+    type TupleVariantState = EncoderState;
 
     fn serialize_bool(&mut self, v: bool) -> Result<(), Error> {
         self.emit_value(Value::Boolean(v))
     }
+
     fn serialize_i64(&mut self, v: i64) -> Result<(), Error> {
         self.emit_value(Value::Integer(v))
     }
+
+    // TODO: checked casts
+
     fn serialize_u64(&mut self, v: u64) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_isize(&mut self, v: isize) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_usize(&mut self, v: usize) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_i8(&mut self, v: i8) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_u8(&mut self, v: u8) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_i16(&mut self, v: i16) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_u16(&mut self, v: u16) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_i32(&mut self, v: i32) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_u32(&mut self, v: u32) -> Result<(), Error> {
         self.serialize_i64(v as i64)
     }
+
     fn serialize_f32(&mut self, v: f32) -> Result<(), Error> {
         self.serialize_f64(v as f64)
     }
+
     fn serialize_f64(&mut self, v: f64) -> Result<(), Error> {
         self.emit_value(Value::Float(v))
     }
+
     fn serialize_str(&mut self, value: &str) -> Result<(), Error> {
         self.emit_value(Value::String(value.to_string()))
     }
+
     fn serialize_unit_struct(&mut self, _name: &'static str) -> Result<(), Error> {
         Ok(())
     }
+
     fn serialize_unit(&mut self) -> Result<(), Error> {
         Ok(())
     }
+
     fn serialize_none(&mut self) -> Result<(), Error> {
         self.emit_none()
     }
+
     fn serialize_char(&mut self, c: char) -> Result<(), Error> {
         self.serialize_str(&c.to_string())
     }
+
     fn serialize_some<V>(&mut self, value: V) -> Result<(), Error>
         where V: ser::Serialize
     {
         value.serialize(self)
     }
+
     fn serialize_bytes(&mut self, v: &[u8]) -> Result<(), Error> {
         let mut state = try!(self.serialize_seq(Some(v.len())));
         for c in v {
@@ -78,93 +127,152 @@ impl ser::Serializer for Encoder {
         }
         self.serialize_seq_end(state)
     }
-    fn serialize_seq_fixed_size(&mut self, len: usize) -> Result<State, Error> {
+
+    fn serialize_seq_fixed_size(&mut self, len: usize)
+                                -> Result<EncoderState, Error> {
         self.serialize_seq(Some(len))
     }
-    fn serialize_seq(&mut self, _len: Option<usize>) -> Result<State, Error> {
-        self.seq_begin()
+
+    fn serialize_seq(&mut self, _len: Option<usize>)
+                     -> Result<EncoderState, Error> {
+        self.seq_begin().map(|s| EncoderState { inner: s })
     }
-    fn serialize_seq_elt<T>(&mut self, _state: &mut State, value: T) -> Result<(), Error>
+
+    fn serialize_seq_elt<T>(&mut self,
+                            _state: &mut EncoderState,
+                            value: T) -> Result<(), Error>
         where T: ser::Serialize
     {
         value.serialize(self)
     }
-    fn serialize_seq_end(&mut self, state: State) -> Result<(), Error> {
-        self.seq_end(state)
+
+    fn serialize_seq_end(&mut self, state: EncoderState) -> Result<(), Error> {
+        self.seq_end(state.inner)
     }
-    fn serialize_tuple(&mut self, len: usize) -> Result<State, Error> {
+
+    fn serialize_tuple(&mut self, len: usize)
+                       -> Result<EncoderState, Error> {
         self.serialize_seq(Some(len))
     }
-    fn serialize_tuple_elt<T>(&mut self, state: &mut State, value: T) -> Result<(), Error>
+
+    fn serialize_tuple_elt<T>(&mut self,
+                              state: &mut EncoderState,
+                              value: T) -> Result<(), Error>
         where T: ser::Serialize
     {
         self.serialize_seq_elt(state, value)
     }
-    fn serialize_tuple_end(&mut self, state: State) -> Result<(), Error> {
+
+    fn serialize_tuple_end(&mut self, state: EncoderState) -> Result<(), Error> {
         self.serialize_seq_end(state)
     }
-    fn serialize_tuple_struct(&mut self, _name: &'static str, len: usize) -> Result<State, Error> {
+
+    fn serialize_tuple_struct(&mut self,
+                              _name: &'static str,
+                              len: usize) -> Result<EncoderState, Error> {
         self.serialize_seq(Some(len))
     }
-    fn serialize_tuple_struct_elt<T>(&mut self, state: &mut State, value: T) -> Result<(), Error>
+
+    fn serialize_tuple_struct_elt<T>(&mut self,
+                                     state: &mut EncoderState,
+                                     value: T) -> Result<(), Error>
         where T: ser::Serialize
     {
         self.serialize_seq_elt(state, value)
     }
-    fn serialize_tuple_struct_end(&mut self, state: State) -> Result<(), Error> {
+
+    fn serialize_tuple_struct_end(&mut self, state: EncoderState)
+                                  -> Result<(), Error> {
         self.serialize_seq_end(state)
     }
-    fn serialize_tuple_variant(&mut self, _name: &'static str, _id: usize, _variant: &'static str, len: usize) -> Result<State, Error> {
+
+    fn serialize_tuple_variant(&mut self,
+                               _name: &'static str,
+                               _id: usize,
+                               _variant: &'static str,
+                               len: usize) -> Result<EncoderState, Error> {
         self.serialize_seq(Some(len))
     }
-    fn serialize_tuple_variant_elt<T>(&mut self, state: &mut State, value: T) -> Result<(), Error>
+
+    fn serialize_tuple_variant_elt<T>(&mut self,
+                                      state: &mut EncoderState,
+                                      value: T) -> Result<(), Error>
         where T: ser::Serialize
     {
         self.serialize_seq_elt(state, value)
     }
-    fn serialize_tuple_variant_end(&mut self, state: State) -> Result<(), Error> {
+
+    fn serialize_tuple_variant_end(&mut self, state: EncoderState)
+                                   -> Result<(), Error> {
         self.serialize_seq_end(state)
     }
+
     fn serialize_map(&mut self, _len: Option<usize>) -> Result<Self, Error> {
         self.table_begin()
     }
-    fn serialize_map_key<K>(&mut self, _state: &mut Encoder, key: K) -> Result<(), Error>
+
+    fn serialize_map_key<K>(&mut self,
+                            _state: &mut Encoder,
+                            key: K) -> Result<(), Error>
         where K: ser::Serialize
     {
         self.table_key(|me| key.serialize(me))
     }
-    fn serialize_map_value<V>(&mut self, _state: &mut Encoder, value: V) -> Result<(), Error>
+
+    fn serialize_map_value<V>(&mut self,
+                              _state: &mut Encoder,
+                              value: V) -> Result<(), Error>
         where V: ser::Serialize
     {
         value.serialize(self)
     }
+
     fn serialize_map_end(&mut self, state: Self) -> Result<(), Error> {
         self.table_end(state)
     }
-    fn serialize_struct(&mut self, _name: &'static str, len: usize) -> Result<Self, Error> {
+
+    fn serialize_struct(&mut self,
+                        _name: &'static str,
+                        len: usize) -> Result<Self, Error> {
         self.serialize_map(Some(len))
     }
-    fn serialize_struct_elt<V>(&mut self, state: &mut Encoder, key: &'static str, value: V) -> Result<(), Error>
+
+    fn serialize_struct_elt<V>(&mut self,
+                               state: &mut Encoder,
+                               key: &'static str,
+                               value: V) -> Result<(), Error>
         where V: ser::Serialize
     {
         try!(self.serialize_map_key(state, key));
         self.serialize_map_value(state, value)
     }
+
     fn serialize_struct_end(&mut self, state: Self) -> Result<(), Error> {
         self.serialize_map_end(state)
     }
-    fn serialize_struct_variant(&mut self, _name: &'static str, _id: usize, _variant: &'static str, len: usize) -> Result<Self, Error> {
+
+    fn serialize_struct_variant(&mut self,
+                                _name: &'static str,
+                                _id: usize,
+                                _variant: &'static str,
+                                len: usize) -> Result<Self, Error> {
         self.serialize_map(Some(len))
     }
-    fn serialize_struct_variant_elt<V>(&mut self, state: &mut Encoder, key: &'static str, value: V) -> Result<(), Error>
+
+    fn serialize_struct_variant_elt<V>(&mut self,
+                                       state: &mut Encoder,
+                                       key: &'static str,
+                                       value: V) -> Result<(), Error>
         where V: ser::Serialize
     {
         try!(self.serialize_map_key(state, key));
         self.serialize_map_value(state, value)
     }
+
     fn serialize_struct_variant_end(&mut self, state: Self) -> Result<(), Error> {
         self.serialize_map_end(state)
     }
+
     fn serialize_newtype_struct<T>(&mut self,
                                    _name: &'static str,
                                    value: T) -> Result<(), Self::Error>
@@ -173,6 +281,7 @@ impl ser::Serializer for Encoder {
         // Don't serialize the newtype struct in a tuple.
         value.serialize(self)
     }
+
     fn serialize_newtype_variant<T>(&mut self,
                                     _name: &'static str,
                                     _variant_index: usize,
@@ -183,6 +292,7 @@ impl ser::Serializer for Encoder {
         // Don't serialize the newtype struct variant in a tuple.
         value.serialize(self)
     }
+
     fn serialize_unit_variant(&mut self,
                                _name: &'static str,
                                _variant_index: usize,
diff --git a/src/lib.rs b/src/lib.rs
index a8e7dbb..e8dcb92 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -48,7 +48,7 @@ use std::str::FromStr;
 pub use parser::{Parser, ParserError};
 
 #[cfg(any(feature = "rustc-serialize", feature = "serde"))]
-pub use self::encoder::{Encoder, Error, encode, encode_str};
+pub use self::encoder::{Encoder, Error, EncoderState, encode, encode_str};
 #[cfg(any(feature = "rustc-serialize", feature = "serde"))]
 pub use self::decoder::{Decoder, DecodeError, DecodeErrorKind, decode, decode_str};