diff --git a/js/indexes.js b/js/indexes.js
index 0bb91f7835..756dc9aeee 100644
--- a/js/indexes.js
+++ b/js/indexes.js
@@ -756,5 +756,10 @@ AJAX.registerOnload('indexes.js', function () {
         }
 
         PMA_showAddIndexDialog(source_array, array_index, target_columns, -1, source_array[array_index]);
-    })
+    });
+
+    $('#index_frm').on('submit', function () {
+        if (typeof(this.elements['index[Key_name]'].disabled) != 'undefined')
+            this.elements['index[Key_name]'].disabled = false;
+    });
 });
diff --git a/templates/table/index_form.phtml b/templates/table/index_form.phtml
index 331c601014..31ecb538c2 100644
--- a/templates/table/index_form.phtml
+++ b/templates/table/index_form.phtml
@@ -2,8 +2,7 @@
       method="post"
       name="index_frm"
       id="index_frm"
-      class="ajax"
-      onsubmit="if (typeof(this.elements['index[Key_name]'].disabled) != 'undefined') this.elements['index[Key_name]'].disabled = false;">
+      class="ajax">
 
     <?= PMA\libraries\URL::getHiddenInputs($form_params); ?>
 
diff --git a/templates/table/structure/add_column.phtml b/templates/table/structure/add_column.phtml
index 8ac7ed1cc0..d18db1760c 100644
--- a/templates/table/structure/add_column.phtml
+++ b/templates/table/structure/add_column.phtml
@@ -1,4 +1,4 @@
-<form method="post" action="tbl_addfield.php" id="addColumns" name="addColumns" onsubmit="return checkFormElementInRange(this, 'num_fields', '<?= str_replace('\'', '\\\'', __('You have to add at least one column.')); ?>', 1)">
+<form method="post" action="tbl_addfield.php" id="addColumns" name="addColumns">
     <?= PMA\libraries\URL::getHiddenInputs($GLOBALS['db'], $GLOBALS['table']); ?>
     <?php if (PMA\libraries\Util::showIcons('ActionLinksMode')): ?>
         <?= PMA\libraries\Util::getImage('b_insrow.png', __('Add column')); ?>&nbsp;