--- a/dom/media/test/eme.js
+++ b/dom/media/test/eme.js
@@ -126,17 +126,17 @@ function UpdateSessionFunc(test, token, 
       if (key) {
         Log(token, "found key " + key + " for key id " + idHex);
         outKeys.push({
           "kty":"oct",
           "kid":id64,
           "k":HexToBase64(key)
         });
       } else {
-        bail(token + " couldn't find key for key id " + idHex);
+        bail(token + " couldn't find key for key id " + idHex)("No such key");
       }
     }
 
     var update = JSON.stringify({
       "keys" : outKeys,
       "type" : msg.type
     });
     Log(token, "sending update message to CDM: " + update);