diff --git a/browser/components/extensions/test/browser/browser_ext_sidebarAction_incognito.js b/browser/components/extensions/test/browser/browser_ext_sidebarAction_incognito.js
index 899618413caa..cad1cb4ccb16 100644
--- a/browser/components/extensions/test/browser/browser_ext_sidebarAction_incognito.js
+++ b/browser/components/extensions/test/browser/browser_ext_sidebarAction_incognito.js
@@ -3,7 +3,7 @@
 "use strict";
 
 add_task(async function test_sidebarAction_not_allowed() {
-  SpecialPowers.pushPrefEnv({
+  await SpecialPowers.pushPrefEnv({
     set: [["extensions.allowPrivateBrowsingByDefault", false]],
   });