diff --git a/lib/javascript-static.js b/lib/javascript-static.js
index 9e59278b583..5d023cd0f7a 100644
--- a/lib/javascript-static.js
+++ b/lib/javascript-static.js
@@ -798,7 +798,7 @@ M.util.js_watch_io = function() {
                 after: ['io-base']
             },
             'io-base': {
-                requires: ['moodle-core-io'],
+                requires: ['moodle-core-io']
             }
         }
     });