1 files changed, 1 insertions, 1 deletions
diff --git a/browser/components/urlbar/tests/browser-updateResults/head.js b/browser/components/urlbar/tests/browser-updateResults/head.js
index 3d46d83018..77b110990e 100644
--- a/browser/components/urlbar/tests/browser-updateResults/head.js
+++ b/browser/components/urlbar/tests/browser-updateResults/head.js
@@ -386,7 +386,7 @@ async function doSuggestedIndexTest({ search1, search2, duringUpdate }) {
   // update and delaying resolving the provider's finishQueryPromise.
   let mutationPromise = new Promise(resolve => {
     let lastRowState = duringUpdate[duringUpdate.length - 1];
-    let observer = new MutationObserver(mutations => {
+    let observer = new MutationObserver(() => {
       observer.disconnect();
       resolve();
     });