diff --git a/src/test/auxiliary/go_trait.rs b/src/test/auxiliary/go_trait.rs
index ab1051c56501..044bb606b40e 100644
--- a/src/test/auxiliary/go_trait.rs
+++ b/src/test/auxiliary/go_trait.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 // Common code used for tests that model the Fn/FnMut/FnOnce hierarchy.
 
 pub trait Go {
diff --git a/src/test/auxiliary/specialization_cross_crate.rs b/src/test/auxiliary/specialization_cross_crate.rs
index 92c985a3e1dd..1d235336de82 100644
--- a/src/test/auxiliary/specialization_cross_crate.rs
+++ b/src/test/auxiliary/specialization_cross_crate.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 pub trait Foo {
     fn foo(&self) -> &'static str;
 }
diff --git a/src/test/compile-fail/specialization-default-projection.rs b/src/test/compile-fail/specialization-default-projection.rs
index b85dba126e61..3f85a503f62d 100644
--- a/src/test/compile-fail/specialization-default-projection.rs
+++ b/src/test/compile-fail/specialization-default-projection.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 // Make sure we can't project defaulted associated types
 
 trait Foo {
diff --git a/src/test/compile-fail/specialization-default-types.rs b/src/test/compile-fail/specialization-default-types.rs
index f6b2dd46efc2..dce1db06a92b 100644
--- a/src/test/compile-fail/specialization-default-types.rs
+++ b/src/test/compile-fail/specialization-default-types.rs
@@ -12,6 +12,8 @@
 // associated type in the impl defining it -- otherwise, what happens
 // if it's overridden?
 
+#![feature(specialization)]
+
 trait Example {
     type Output;
     fn generate(self) -> Self::Output;
diff --git a/src/test/compile-fail/specialization-feature-gate-default.rs b/src/test/compile-fail/specialization-feature-gate-default.rs
new file mode 100644
index 000000000000..caac21278d46
--- /dev/null
+++ b/src/test/compile-fail/specialization-feature-gate-default.rs
@@ -0,0 +1,19 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+trait Foo {
+    fn foo(&self);
+}
+
+impl<T> Foo for T {
+    default fn foo(&self) {} //~ ERROR
+}
+
+fn main() {}
diff --git a/src/test/compile-fail/specialization-feature-gate-overlap.rs b/src/test/compile-fail/specialization-feature-gate-overlap.rs
new file mode 100644
index 000000000000..a7918e4426d9
--- /dev/null
+++ b/src/test/compile-fail/specialization-feature-gate-overlap.rs
@@ -0,0 +1,23 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+trait Foo {
+    fn foo(&self);
+}
+
+impl<T> Foo for T {
+    fn foo(&self) {}
+}
+
+impl Foo for u8 { //~ ERROR
+    fn foo(&self) {}
+}
+
+fn main() {}
diff --git a/src/test/compile-fail/specialization-negative-impl.rs b/src/test/compile-fail/specialization-negative-impl.rs
index d0d698d12e09..3a907dc3b8e7 100644
--- a/src/test/compile-fail/specialization-negative-impl.rs
+++ b/src/test/compile-fail/specialization-negative-impl.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 #![feature(optin_builtin_traits)]
+#![feature(specialization)]
 
 struct TestType<T>(T);
 
diff --git a/src/test/compile-fail/specialization-no-default.rs b/src/test/compile-fail/specialization-no-default.rs
index 3e23c6e06eaf..143c6f0e8582 100644
--- a/src/test/compile-fail/specialization-no-default.rs
+++ b/src/test/compile-fail/specialization-no-default.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 trait Foo {
     fn foo(&self);
     fn bar(&self);
diff --git a/src/test/compile-fail/specialization-overlap-negative.rs b/src/test/compile-fail/specialization-overlap-negative.rs
index cc427b4fed21..62a6d8d9b503 100644
--- a/src/test/compile-fail/specialization-overlap-negative.rs
+++ b/src/test/compile-fail/specialization-overlap-negative.rs
@@ -9,6 +9,7 @@
 // except according to those terms.
 
 #![feature(optin_builtin_traits)]
+#![feature(specialization)]
 
 trait MyTrait {}
 
diff --git a/src/test/compile-fail/specialization-overlap.rs b/src/test/compile-fail/specialization-overlap.rs
index 7d14e85fba83..57529d2ae426 100644
--- a/src/test/compile-fail/specialization-overlap.rs
+++ b/src/test/compile-fail/specialization-overlap.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 trait Foo {}
 impl<T: Clone> Foo for T {}
 impl<T> Foo for Vec<T> {} //~ ERROR E0119
diff --git a/src/test/run-pass/specialization-allowed-cross-crate.rs b/src/test/run-pass/specialization-allowed-cross-crate.rs
index 139c63d3cdb4..6b999f383583 100644
--- a/src/test/run-pass/specialization-allowed-cross-crate.rs
+++ b/src/test/run-pass/specialization-allowed-cross-crate.rs
@@ -10,6 +10,8 @@
 
 // aux-build:go_trait.rs
 
+#![feature(specialization)]
+
 extern crate go_trait;
 
 use go_trait::{Go,GoMut};
diff --git a/src/test/run-pass/specialization-assoc-fns.rs b/src/test/run-pass/specialization-assoc-fns.rs
index 750581ffe923..683e0d55dc94 100644
--- a/src/test/run-pass/specialization-assoc-fns.rs
+++ b/src/test/run-pass/specialization-assoc-fns.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 trait Foo {
     fn mk() -> Self;
 }
diff --git a/src/test/run-pass/specialization-basics.rs b/src/test/run-pass/specialization-basics.rs
index e585c8e23535..b11495e9edf1 100644
--- a/src/test/run-pass/specialization-basics.rs
+++ b/src/test/run-pass/specialization-basics.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 // Tests a variety of basic specialization scenarios and method
 // dispatch for them.
 
diff --git a/src/test/run-pass/specialization-cross-crate.rs b/src/test/run-pass/specialization-cross-crate.rs
index c74b1f2e49e4..7593ac4fb1dd 100644
--- a/src/test/run-pass/specialization-cross-crate.rs
+++ b/src/test/run-pass/specialization-cross-crate.rs
@@ -10,6 +10,8 @@
 
 // aux-build:specialization_cross_crate.rs
 
+#![feature(specialization)]
+
 extern crate specialization_cross_crate;
 
 use specialization_cross_crate::*;
diff --git a/src/test/run-pass/specialization-default-methods.rs b/src/test/run-pass/specialization-default-methods.rs
index 7482d3acbc1a..9c52ceb52472 100644
--- a/src/test/run-pass/specialization-default-methods.rs
+++ b/src/test/run-pass/specialization-default-methods.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 // First, test only use of explicit `default` items:
 
 trait Foo {
diff --git a/src/test/run-pass/specialization-on-projection.rs b/src/test/run-pass/specialization-on-projection.rs
index f20615326622..65cbb31d2214 100644
--- a/src/test/run-pass/specialization-on-projection.rs
+++ b/src/test/run-pass/specialization-on-projection.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 trait Foo<T> {}
 
 trait Assoc {
diff --git a/src/test/run-pass/specialization-projection.rs b/src/test/run-pass/specialization-projection.rs
index 86fcab1fdc28..d26d59896a57 100644
--- a/src/test/run-pass/specialization-projection.rs
+++ b/src/test/run-pass/specialization-projection.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 // Make sure we *can* project non-defaulted associated types
 // cf compile-fail/specialization-default-projection.rs
 
diff --git a/src/test/run-pass/specialization-super-traits.rs b/src/test/run-pass/specialization-super-traits.rs
index 4a30e6bcd25f..a9b3bfca53d1 100644
--- a/src/test/run-pass/specialization-super-traits.rs
+++ b/src/test/run-pass/specialization-super-traits.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 // Test that you can specialize via an explicit trait hierarchy
 
 // FIXME: this doesn't work yet...
diff --git a/src/test/run-pass/specialization-translate-projections-with-params.rs b/src/test/run-pass/specialization-translate-projections-with-params.rs
index 6bca8939d82a..3d90bc56f42b 100644
--- a/src/test/run-pass/specialization-translate-projections-with-params.rs
+++ b/src/test/run-pass/specialization-translate-projections-with-params.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 trait Trait<T> {
     fn convert(&self) -> T;
 }
diff --git a/src/test/run-pass/specialization-translate-projections.rs b/src/test/run-pass/specialization-translate-projections.rs
index 7f41729a527d..d224efe8c318 100644
--- a/src/test/run-pass/specialization-translate-projections.rs
+++ b/src/test/run-pass/specialization-translate-projections.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(specialization)]
+
 use std::convert::Into;
 
 trait Trait {