diff --git a/common/modules/base.jsm b/common/modules/base.jsm
index 96d4f083..024be9d9 100644
--- a/common/modules/base.jsm
+++ b/common/modules/base.jsm
@@ -1607,6 +1607,7 @@ update(iter, {
                 return i;
             i++;
         }
+        return -1;
     },
 
     /**