diff --git a/src/libs/webfix.js b/src/libs/webfix.js
index 6168770..546c4c1 100644
--- a/src/libs/webfix.js
+++ b/src/libs/webfix.js
@@ -148,7 +148,7 @@ function run(selector, fixer, rootSelector) {
   var mutaObserver = new MutationObserver(function (mutations) {
     mutations.forEach(function (mutation) {
       mutation.addedNodes.forEach(function (addNode) {
-        addNode.querySelectorAll(selector).forEach(fixer);
+        addNode?.querySelectorAll(selector).forEach(fixer);
       });
     });
   });