diff --git a/serde/Cargo.toml b/serde/Cargo.toml
index ad3a5de3..2209d58b 100644
--- a/serde/Cargo.toml
+++ b/serde/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "serde"
-version = "0.6.6"
+version = "0.6.7"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "A generic serialization/deserialization framework"
diff --git a/serde/src/lib.rs b/serde/src/lib.rs
index 380029c7..e4072d1c 100644
--- a/serde/src/lib.rs
+++ b/serde/src/lib.rs
@@ -10,7 +10,7 @@
 //! [github repository](https://github.com/serde-rs/serde)
 
 #![doc(html_root_url="https://serde-rs.github.io/serde/serde")]
-#![cfg_attr(feature = "nightly", feature(collections, core, enumset, nonzero, step_trait, zero_one))]
+#![cfg_attr(feature = "nightly", feature(collections, enumset, nonzero, step_trait, zero_one))]
 
 #![deny(missing_docs)]
 
diff --git a/serde_codegen/Cargo.toml b/serde_codegen/Cargo.toml
index 84086296..7d71b247 100644
--- a/serde_codegen/Cargo.toml
+++ b/serde_codegen/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "serde_codegen"
-version = "0.6.5"
+version = "0.6.8"
 authors = ["Erick Tryzelaar <erick.tryzelaar@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Macros to auto-generate implementations for the serde framework"
@@ -15,12 +15,12 @@ nightly = ["quasi_macros"]
 with-syntex = ["quasi/with-syntex", "quasi_codegen", "quasi_codegen/with-syntex", "syntex", "syntex_syntax"]
 
 [build-dependencies]
-quasi_codegen = { version = "^0.3.9", optional = true }
-syntex = { version = "^0.22.0", optional = true }
+quasi_codegen = { version = "^0.3.12", optional = true }
+syntex = { version = "^0.25.0", optional = true }
 
 [dependencies]
-aster = { version = "^0.9.0", default-features = false }
-quasi = { version = "^0.3.9", default-features = false }
-quasi_macros = { version = "^0.3.9", optional = true }
-syntex = { version = "^0.22.0", optional = true }
-syntex_syntax = { version = "^0.23.0", optional = true }
+aster = { version = "^0.9.3", default-features = false }
+quasi = { version = "^0.3.12", default-features = false }
+quasi_macros = { version = "^0.3.12", optional = true }
+syntex = { version = "^0.25.0", optional = true }
+syntex_syntax = { version = "^0.25.0", optional = true }
diff --git a/serde_codegen/src/de.rs b/serde_codegen/src/de.rs
index 2475b46f..b257091a 100644
--- a/serde_codegen/src/de.rs
+++ b/serde_codegen/src/de.rs
@@ -5,7 +5,6 @@ use aster;
 use syntax::ast::{
     self,
     EnumDef,
-    Expr,
     Ident,
     Item,
     MetaItem,
@@ -13,7 +12,6 @@ use syntax::ast::{
 use syntax::codemap::Span;
 use syntax::ext::base::{Annotatable, ExtCtxt};
 use syntax::ext::build::AstBuilder;
-use syntax::owned_slice::OwnedSlice;
 use syntax::ptr::P;
 
 use attr;
@@ -187,7 +185,7 @@ fn deserialize_visitor(
         let mut trait_generics = trait_generics.clone();
         let mut ty_params = forward_ty_params.clone();
         ty_params.extend(trait_generics.ty_params.into_vec());
-        trait_generics.ty_params = OwnedSlice::from_vec(ty_params);
+        trait_generics.ty_params = P::from_vec(ty_params);
 
         (
             builder.item().tuple_struct("__Visitor")
diff --git a/serde_codegen/src/ser.rs b/serde_codegen/src/ser.rs
index f073488f..847131e6 100644
--- a/serde_codegen/src/ser.rs
+++ b/serde_codegen/src/ser.rs
@@ -4,7 +4,6 @@ use syntax::ast::{
     Ident,
     MetaItem,
     Item,
-    Expr,
 };
 use syntax::ast;
 use syntax::codemap::Span;
diff --git a/serde_tests/Cargo.toml b/serde_tests/Cargo.toml
index ac2a0ea4..31ad0e3d 100644
--- a/serde_tests/Cargo.toml
+++ b/serde_tests/Cargo.toml
@@ -11,15 +11,15 @@ keywords = ["serialization"]
 build = "build.rs"
 
 [build-dependencies]
-syntex = { version = "^0.22.0" }
-syntex_syntax = { version = "^0.23.0" }
+syntex = { version = "^0.25.0" }
+syntex_syntax = { version = "^0.25.0" }
 serde_codegen = { version = "*", path = "../serde_codegen", features = ["with-syntex"] }
 
 [dev-dependencies]
 num = "^0.1.27"
 rustc-serialize = "^0.3.16"
 serde = { version = "*", path = "../serde", features = ["num-impls"] }
-syntex = "^0.22.0"
+syntex = "^0.25.0"
 
 [[test]]
 name = "test"