diff --git a/src/libstd/str.rs b/src/libstd/str.rs
index 81c9cde312e3..0b270edc5342 100644
--- a/src/libstd/str.rs
+++ b/src/libstd/str.rs
@@ -959,6 +959,14 @@ pub mod raw {
         ::cast::transmute(v)
     }
 
+    #[lang="strdup_uniq"]
+    #[cfg(not(test))]
+    #[allow(missing_doc)]
+    #[inline]
+    pub unsafe fn strdup_uniq(ptr: *u8, len: uint) -> ~str {
+        from_buf_len(ptr, len)
+    }
+
     /// Create a Rust string from a null-terminated C string
     pub unsafe fn from_c_str(buf: *libc::c_char) -> ~str {
         let mut curr = buf;
diff --git a/src/libstd/unstable/lang.rs b/src/libstd/unstable/lang.rs
index 9e7ac1fd7db1..f5074e085580 100644
--- a/src/libstd/unstable/lang.rs
+++ b/src/libstd/unstable/lang.rs
@@ -93,12 +93,6 @@ pub unsafe fn check_not_borrowed(a: *u8,
     borrowck::check_not_borrowed(a, file, line)
 }
 
-#[lang="strdup_uniq"]
-#[inline]
-pub unsafe fn strdup_uniq(ptr: *c_uchar, len: uint) -> ~str {
-    str::raw::from_buf_len(ptr, len)
-}
-
 #[lang="annihilate"]
 pub unsafe fn annihilate() {
     ::cleanup::annihilate()