--- a/testing/mochitest/mochitest.eslintrc.js
+++ b/testing/mochitest/mochitest.eslintrc.js
@@ -6,16 +6,20 @@ module.exports = {
     "no-shadow": "error",
   },
 
   "env": {
     "browser": true,
     "mozilla/simpletest": true,
   },
 
+  "plugins": [
+    "mozilla"
+  ],
+
   // All globals made available in the test environment.
   "globals": {
     // `$` is defined in SimpleTest.js
     "$": false,
     "add_task": false,
     "addLoadEvent": false,
     "Assert": false,
     "EventUtils": false,