diff --git a/tools/wds-monkey-patch.js b/tools/wds-monkey-patch.js
index dd24d5e..fbc67c3 100644
--- a/tools/wds-monkey-patch.js
+++ b/tools/wds-monkey-patch.js
@@ -14,6 +14,8 @@ export const monkeyPatchCJS = () => ({
             export class Readable {};
             export class Writable {};
           `
+    } else if (context.path.endsWith('eventemitter3/index.js')) {
+      return 'export default class EventEmitter {};';
     }
   }
 })