2 files changed, 5 insertions, 0 deletions
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index 741cf7b47fa..cf427c16588 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -624,6 +624,7 @@ impl<'a> Formatter<'a> {
     /// # Examples
     ///
     /// ```rust
+    /// # #![feature(debug_builders, core)]
     /// use std::fmt;
     ///
     /// struct Foo {
@@ -655,6 +656,7 @@ impl<'a> Formatter<'a> {
     /// # Examples
     ///
     /// ```rust
+    /// # #![feature(debug_builders, core)]
     /// use std::fmt;
     ///
     /// struct Foo(i32, String);
@@ -683,6 +685,7 @@ impl<'a> Formatter<'a> {
     /// # Examples
     ///
     /// ```rust
+    /// # #![feature(debug_builders, core)]
     /// use std::fmt;
     ///
     /// struct Foo(Vec<i32>);
@@ -712,6 +715,7 @@ impl<'a> Formatter<'a> {
     /// # Examples
     ///
     /// ```rust
+    /// # #![feature(debug_builders, core)]
     /// use std::fmt;
     ///
     /// struct Foo(Vec<(String, i32)>);
diff --git a/src/libcore/fmt/num.rs b/src/libcore/fmt/num.rs
index fe22ee60da6..49da99b97cb 100644
--- a/src/libcore/fmt/num.rs
+++ b/src/libcore/fmt/num.rs
@@ -146,6 +146,7 @@ pub struct RadixFmt<T, R>(T, R);
 /// # Examples
 ///
 /// ```
+/// # #![feature(core)]
 /// use std::fmt::radix;
 /// assert_eq!(format!("{}", radix(55, 36)), "1j".to_string());
 /// ```