diff --git a/WindowScript.js b/WindowScript.js
index a9e2e64..34965c7 100644
--- a/WindowScript.js
+++ b/WindowScript.js
@@ -70,8 +70,14 @@
             },
         };
     }
-
-    window.parent = new Proxy(window.parent, handle('parent'));
-    window.opener = new Proxy(window.opener, handle('opener'));
+    
+    if (window.parent !== window) {
+        window.parent = new Proxy(window.parent, handle('parent'));
+    }
+    
+    if (window.opener) {
+        window.opener = new Proxy(window.opener, handle('opener'));
+    }
+    
     window.postMessage = new Proxy(window.postMessage, handle('self'));
 })();