diff --git a/js/pacosako_ui.js b/js/pacosako_ui.js
index 8163b44..5a221f4 100644
--- a/js/pacosako_ui.js
+++ b/js/pacosako_ui.js
@@ -789,12 +789,15 @@ $(function (){
    });
 
    $('#cb_nav_prev_turn').on('click', function(){
-      const player = visibleGame.player;
-      while (visibleGame.canUndo) {
+      if (visibleGame.canUndo) {
          visibleGame.undo();
-         if (visibleGame.player === player) {
-            visibleGame.redo();
-            break;
+         const player = visibleGame.player;
+         while (visibleGame.canUndo) {
+            visibleGame.undo();
+            if (visibleGame.player !== player) {
+               visibleGame.redo();
+               break;
+            }
          }
       }
       renderBoard();