diff --git a/browser/components/prefwindow/content/pref-features.js b/browser/components/prefwindow/content/pref-features.js
index 5ed72eb587d3..bc489d4b758a 100644
--- a/browser/components/prefwindow/content/pref-features.js
+++ b/browser/components/prefwindow/content/pref-features.js
@@ -176,7 +176,7 @@ function DeleteAllFromTree
 
 
   // disable buttons
-  permissionsExist = false;
+  persissionsExist = false;
   togglePermissionEnabling();
 }