diff --git a/tests/wpt/web-platform-tests/websockets/websocket.js b/tests/wpt/web-platform-tests/websockets/websocket.js
index 79b7bd59c58..4b44a41608e 100644
--- a/tests/wpt/web-platform-tests/websockets/websocket.js
+++ b/tests/wpt/web-platform-tests/websockets/websocket.js
@@ -25,7 +25,7 @@ var closeCode;
 var urlToOpen;
 
 function IsWebSocket() {
-    if (!window.WebSocket) {
+    if (!self.WebSocket) {
         assert_true(false, "Browser does not support WebSocket");
     }
 }