1 files changed, 7 insertions, 0 deletions
diff --git a/src/libsyntax/attr.rs b/src/libsyntax/attr.rs
index c5cffc401a1..416fc8c2278 100644
--- a/src/libsyntax/attr.rs
+++ b/src/libsyntax/attr.rs
@@ -28,6 +28,7 @@ use ptr::P;
 use std::cell::{RefCell, Cell};
 use std::collections::BitvSet;
 use std::collections::HashSet;
+use std::fmt;
 
 thread_local! { static USED_ATTRS: RefCell<BitvSet> = RefCell::new(BitvSet::new()) }
 
@@ -357,6 +358,12 @@ pub enum StabilityLevel {
     Locked
 }
 
+impl fmt::String for StabilityLevel {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        fmt::Show::fmt(self, f)
+    }
+}
+
 pub fn find_stability_generic<'a,
                               AM: AttrMetaMethods,
                               I: Iterator<Item=&'a AM>>