diff --git a/packages/core/event-emitter.js b/packages/core/event-emitter.js
index 3fe2d1d..f65a230 100644
--- a/packages/core/event-emitter.js
+++ b/packages/core/event-emitter.js
@@ -77,12 +77,10 @@ export function EventEmitterMixin(Superclass) {
         return;
       }
       // Function.
-      const lists = [];
-      if ((type in this.$$events)) {
-        lists.push(this.$$events);
+      if (!(type in this.$$events)) {
+        return;
       }
-      const listeners = this.$$events;
-      listeners[type] = listeners[type].filter((listener) => {
+      this.$$events[type] = this.$$events[type].filter((listener) => {
         return listener.fn !== fn;
       });
     }