diff --git a/static/js/move_to_month.js b/static/js/move_to_month.js
index 6cffa99..1700b56 100644
--- a/static/js/move_to_month.js
+++ b/static/js/move_to_month.js
@@ -1,7 +1,8 @@
   function updateMoveToMonth() {
     const year = document.getElementById('move_to_month_year').value;
     const month = document.getElementById('move_to_month_month').value;
-    document.getElementById('move_to_month').value = `${year}-${month}`;
+    const hiddenInput = document.getElementById('move_to_month');
+    hiddenInput.value = `${year}-${month}`;
   }
 
   document.getElementById('move_to_month_year').addEventListener('change', updateMoveToMonth);