diff --git a/ace-window.el b/ace-window.el
index 1e3d0b1..237a3ff 100644
--- a/ace-window.el
+++ b/ace-window.el
@@ -537,8 +537,9 @@ Windows are numbered top down, left to right."
         (f2 (window-frame wnd2))
         (e1 (window-edges wnd1))
         (e2 (window-edges wnd2)))
-    (cond ((string< (frame-parameter f1 'window-id)
-                    (frame-parameter f2 'window-id))
+    (cond ((< (car (frame-position f1)) (car (frame-position f2)))
+           (not aw-reverse-frame-list))
+          ((> (car (frame-position f1)) (car (frame-position f2)))
            aw-reverse-frame-list)
           ((< (car e1) (car e2))
            t)