diff --git a/extensions/layout-debug/src/nsRegressionTester.cpp b/extensions/layout-debug/src/nsRegressionTester.cpp
index 1195fb7b86f6..bcd00c4158ae 100644
--- a/extensions/layout-debug/src/nsRegressionTester.cpp
+++ b/extensions/layout-debug/src/nsRegressionTester.cpp
@@ -91,7 +91,10 @@ nsRegressionTester::DumpFrameModel(nsIDOMWindow *aWindowToDump, nsILocalFile *aD
   PRBool      stillLoading;
 
   *aResult = DUMP_RESULT_ERROR;
-  
+
+#ifndef DEBUG
+  return NS_ERROR_NOT_AVAILABLE;
+#else
   nsCOMPtr<nsIDocShell> docShell;
   rv = GetDocShellFromWindow(aWindowToDump, getter_AddRefs(docShell));
   if (NS_FAILED(rv)) return rv;
@@ -133,6 +136,7 @@ nsRegressionTester::DumpFrameModel(nsIDOMWindow *aWindowToDump, nsILocalFile *aD
     fclose(fp);
   *aResult = DUMP_RESULT_COMPLETED;
   return NS_OK;
+#endif
 }
 
 NS_IMETHODIMP