diff --git a/src/liballoc/benches/str.rs b/src/liballoc/benches/str.rs
index fc4063fae927..38c94d4d8b5f 100644
--- a/src/liballoc/benches/str.rs
+++ b/src/liballoc/benches/str.rs
@@ -272,15 +272,12 @@ make_test!(match_indices_a_str, s, s.match_indices("a").count());
 make_test!(split_a_str, s, s.split("a").count());
 
 make_test!(trim_ascii_char, s, {
-    use std::ascii::AsciiExt;
     s.trim_matches(|c: char| c.is_ascii())
 });
 make_test!(trim_left_ascii_char, s, {
-    use std::ascii::AsciiExt;
     s.trim_left_matches(|c: char| c.is_ascii())
 });
 make_test!(trim_right_ascii_char, s, {
-    use std::ascii::AsciiExt;
     s.trim_right_matches(|c: char| c.is_ascii())
 });
 
diff --git a/src/liballoc/borrow.rs b/src/liballoc/borrow.rs
index a662e4b1f4f9..e8aff0998715 100644
--- a/src/liballoc/borrow.rs
+++ b/src/liballoc/borrow.rs
@@ -191,7 +191,6 @@ impl<'a, B: ?Sized> Cow<'a, B>
     /// # Examples
     ///
     /// ```
-    /// use std::ascii::AsciiExt;
     /// use std::borrow::Cow;
     ///
     /// let mut cow = Cow::Borrowed("foo");
diff --git a/src/liballoc/str.rs b/src/liballoc/str.rs
index 2c257b8c7367..b75ecb6ea51c 100644
--- a/src/liballoc/str.rs
+++ b/src/liballoc/str.rs
@@ -390,8 +390,6 @@ impl str {
     /// # Examples
     ///
     /// ```
-    /// use std::ascii::AsciiExt;
-    ///
     /// let mut v = String::from("hello");
     /// // correct length
     /// assert!(v.get_mut(0..5).is_some());
@@ -617,8 +615,6 @@ impl str {
     /// Basic usage:
     ///
     /// ```
-    /// use std::ascii::AsciiExt;
-    ///
     /// let mut s = "Per Martin-Löf".to_string();
     /// {
     ///     let (first, last) = s.split_at_mut(3);
diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index 6d0bb264df18..25fcc1ccdab5 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -773,8 +773,6 @@ impl String {
     /// Basic usage:
     ///
     /// ```
-    /// use std::ascii::AsciiExt;
-    ///
     /// let mut s = String::from("foobar");
     /// let s_mut_str = s.as_mut_str();
     ///
diff --git a/src/liballoc/tests/str.rs b/src/liballoc/tests/str.rs
index b3178064505e..6b075e7ac0e0 100644
--- a/src/liballoc/tests/str.rs
+++ b/src/liballoc/tests/str.rs
@@ -706,7 +706,6 @@ fn test_split_at() {
 
 #[test]
 fn test_split_at_mut() {
-    use std::ascii::AsciiExt;
     let mut s = "Hello World".to_string();
     {
         let (a, b) = s.split_at_mut(5);
diff --git a/src/liballoc/tests/vec.rs b/src/liballoc/tests/vec.rs
index 0e25da5bd307..9cfde5dcc73c 100644
--- a/src/liballoc/tests/vec.rs
+++ b/src/liballoc/tests/vec.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use std::ascii::AsciiExt;
 use std::borrow::Cow;
 use std::mem::size_of;
 use std::panic;
@@ -966,5 +965,3 @@ fn drain_filter_complex() {
         assert_eq!(vec, vec![1, 3, 5, 7, 9, 11, 13, 15, 17, 19]);
     }
 }
-
-
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index cf34e195dea7..5aca199cf40c 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -853,8 +853,6 @@ impl<T> Vec<T> {
     /// # Examples
     ///
     /// ```
-    /// use std::ascii::AsciiExt;
-    ///
     /// let mut vec = vec!["foo", "bar", "Bar", "baz", "bar"];
     ///
     /// vec.dedup_by(|a, b| a.eq_ignore_ascii_case(b));
diff --git a/src/librustc/lint/mod.rs b/src/librustc/lint/mod.rs
index bca4dad220fc..d648099d74d3 100644
--- a/src/librustc/lint/mod.rs
+++ b/src/librustc/lint/mod.rs
@@ -38,6 +38,7 @@ use hir::def_id::{CrateNum, LOCAL_CRATE};
 use hir::intravisit::{self, FnKind};
 use hir;
 use session::Session;
+#[cfg(stage0)]
 use std::ascii::AsciiExt;
 use std::hash;
 use syntax::ast;
diff --git a/src/librustdoc/clean/cfg.rs b/src/librustdoc/clean/cfg.rs
index e3ce403f3c17..915383d8189e 100644
--- a/src/librustdoc/clean/cfg.rs
+++ b/src/librustdoc/clean/cfg.rs
@@ -15,6 +15,7 @@
 use std::mem;
 use std::fmt::{self, Write};
 use std::ops;
+#[cfg(stage0)]
 use std::ascii::AsciiExt;
 
 use syntax::symbol::Symbol;
diff --git a/src/librustdoc/html/render.rs b/src/librustdoc/html/render.rs
index edd01a66075b..228bd7a03309 100644
--- a/src/librustdoc/html/render.rs
+++ b/src/librustdoc/html/render.rs
@@ -34,6 +34,7 @@
 //! both occur before the crate is rendered.
 pub use self::ExternalLocation::*;
 
+#[cfg(stage0)]
 use std::ascii::AsciiExt;
 use std::cell::RefCell;
 use std::cmp::Ordering;
diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index 200264a25834..96d719c528c1 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -38,8 +38,8 @@ use iter::FusedIterator;
 /// ```
 /// use std::ascii::AsciiExt;
 ///
-/// assert_eq!("café".to_ascii_uppercase(), "CAFÉ");
-/// assert_eq!("café".to_ascii_uppercase(), "CAFé");
+/// assert_eq!(AsciiExt::to_ascii_uppercase("café"), "CAFÉ");
+/// assert_eq!(AsciiExt::to_ascii_uppercase("café"), "CAFé");
 /// ```
 ///
 /// In the first example, the lowercased string is represented `"cafe\u{301}"`
@@ -681,7 +681,9 @@ impl fmt::Debug for EscapeDefault {
 
 #[cfg(test)]
 mod tests {
-    use super::*;
+    //! Note that most of these tests are not testing `AsciiExt` methods, but
+    //! test inherent ascii methods of char, u8, str and [u8]. `AsciiExt` is
+    //! just using those methods, though.
     use char::from_u32;
 
     #[test]
diff --git a/src/test/ui/deref-suggestion.stderr b/src/test/ui/deref-suggestion.stderr
index 5ad9c19fa8cc..3ed3297e05ed 100644
--- a/src/test/ui/deref-suggestion.stderr
+++ b/src/test/ui/deref-suggestion.stderr
@@ -10,8 +10,8 @@ error[E0308]: mismatched types
            - .escape_debug()
            - .escape_default()
            - .escape_unicode()
-           - .to_lowercase()
-           - .to_uppercase()
+           - .to_ascii_lowercase()
+           - .to_ascii_uppercase()
 
 error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:23:10