diff --git a/src/liballoc/tests/lib.rs b/src/liballoc/tests/lib.rs
index 6d774f3fecd9..5723a30c0f34 100644
--- a/src/liballoc/tests/lib.rs
+++ b/src/liballoc/tests/lib.rs
@@ -8,6 +8,7 @@
 #![feature(trusted_len)]
 #![feature(try_reserve)]
 #![feature(unboxed_closures)]
+#![feature(associated_type_bounds)]
 
 use std::hash::{Hash, Hasher};
 use std::collections::hash_map::DefaultHasher;
diff --git a/src/libcore/iter/traits/collect.rs b/src/libcore/iter/traits/collect.rs
index 9f15de33425f..015184cbba25 100644
--- a/src/libcore/iter/traits/collect.rs
+++ b/src/libcore/iter/traits/collect.rs
@@ -194,6 +194,8 @@ pub trait FromIterator<A>: Sized {
 /// `Item`:
 ///
 /// ```rust
+/// #![feature(associated_type_bounds)]
+///
 /// fn collect_as_strings<T>(collection: T) -> Vec<String>
 /// where
 ///     T: IntoIterator<Item: std::fmt::Debug>,
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index cfee49a7b555..10e3c3450631 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -238,6 +238,7 @@
 #![feature(arbitrary_self_types)]
 #![feature(array_error_internals)]
 #![feature(asm)]
+#![feature(associated_type_bounds)]
 #![feature(bind_by_move_pattern_guards)]
 #![feature(box_syntax)]
 #![feature(c_variadic)]