diff --git a/src/libcore/raw.rs b/src/libcore/raw.rs
index 3fd244b46e30..10b9361db63b 100644
--- a/src/libcore/raw.rs
+++ b/src/libcore/raw.rs
@@ -25,7 +25,7 @@ use mem;
 #[repr(C)]
 pub struct Slice<T> {
     pub data: *const T,
-    pub len: uint,
+    pub len: usize,
 }
 
 impl<T> Copy for Slice<T> {}