2 files changed, 3 insertions, 3 deletions
diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index f003948be7b..ded572e82ff 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -14,6 +14,7 @@
 
 use prelude::v1::*;
 
+use mem;
 use ops::Range;
 
 /// Extension methods for ASCII-subset only operations on owned strings
@@ -185,12 +186,12 @@ impl AsciiExt for str {
     }
 
     fn make_ascii_uppercase(&mut self) {
-        let me: &mut [u8] = unsafe { self.as_bytes_mut() };
+        let me: &mut [u8] = unsafe { mem::transmute(self) };
         me.make_ascii_uppercase()
     }
 
     fn make_ascii_lowercase(&mut self) {
-        let me: &mut [u8] = unsafe { self.as_bytes_mut() };
+        let me: &mut [u8] = unsafe { mem::transmute(self) };
         me.make_ascii_lowercase()
     }
 }
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index b4bbb3f25f7..7baa7558e52 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -235,7 +235,6 @@
 #![feature(slice_bytes)]
 #![feature(slice_patterns)]
 #![feature(staged_api)]
-#![feature(str_as_bytes_mut)]
 #![feature(str_char)]
 #![feature(str_internals)]
 #![feature(unboxed_closures)]