1 files changed, 3 insertions, 9 deletions
diff --git a/runtime/js/11_workers.js b/runtime/js/11_workers.js
index 80e85a3a1..4510004d6 100644
--- a/runtime/js/11_workers.js
+++ b/runtime/js/11_workers.js
@@ -5,7 +5,6 @@
   const core = window.Deno.core;
   const {
     Error,
-    ObjectPrototypeIsPrototypeOf,
     StringPrototypeStartsWith,
     String,
     SymbolIterator,
@@ -17,11 +16,8 @@
   const { serializePermissions } = window.__bootstrap.permissions;
   const { log } = window.__bootstrap.util;
   const { defineEventHandler } = window.__bootstrap.event;
-  const {
-    deserializeJsMessageData,
-    serializeJsMessageData,
-    MessagePortPrototype,
-  } = window.__bootstrap.messagePort;
+  const { deserializeJsMessageData, serializeJsMessageData } =
+    window.__bootstrap.messagePort;
 
   function createWorker(
     specifier,
@@ -203,9 +199,7 @@
         const event = new MessageEvent("message", {
           cancelable: false,
           data: message,
-          ports: transferables.filter((t) =>
-            ObjectPrototypeIsPrototypeOf(MessagePortPrototype, t)
-          ),
+          ports: transferables.filter((t) => t instanceof MessagePort),
         });
         this.dispatchEvent(event);
       }