diff --git a/extensions/window-list/extension.js b/extensions/window-list/extension.js
index 19bade7b..e77dde9d 100644
--- a/extensions/window-list/extension.js
+++ b/extensions/window-list/extension.js
@@ -59,9 +59,8 @@ function _onMenuStateChanged(menu, isOpen) {
 
 function _getAppStableSequence(app) {
     return app.get_windows().reduce(function(prev, cur) {
-        let seq = cur.get_stable_sequence();
-        return prev ? Math.min(prev, seq) : seq;
-    }, 0);
+        return Math.min(prev, cur.get_stable_sequence());
+    }, Infinity);
 }