diff --git a/src/libsyntax/ext/bytes.rs b/src/libsyntax/ext/bytes.rs
index cafd1d607005..9f225d55b444 100644
--- a/src/libsyntax/ext/bytes.rs
+++ b/src/libsyntax/ext/bytes.rs
@@ -17,8 +17,6 @@ use ext::base;
 use ext::build::AstBuilder;
 use std::ascii::AsciiExt;
 
-use std::ascii::AsciiCast;
-
 pub fn expand_syntax_ext<'cx>(cx: &'cx mut ExtCtxt,
                               sp: Span,
                               tts: &[ast::TokenTree])
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 45bd28371b58..28f7a78ddd08 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -30,7 +30,6 @@ use visit;
 use visit::Visitor;
 use parse::token;
 
-use std::ascii::AsciiCast;
 use std::slice;
 use std::ascii::AsciiExt;