diff --git a/src/libsyntax/diagnostic.rs b/src/libsyntax/diagnostic.rs
index 0b26a641f8d50..c026a1c97c139 100644
--- a/src/libsyntax/diagnostic.rs
+++ b/src/libsyntax/diagnostic.rs
@@ -211,7 +211,7 @@ pub fn mk_handler(e: Box<Emitter + Send>) -> Handler {
     }
 }
 
-#[deriving(PartialEq)]
+#[deriving(PartialEq, Clone)]
 pub enum Level {
     Bug,
     Fatal,