diff --git a/adminer/create.inc.php b/adminer/create.inc.php
index 50ce9dda..e9fd1d0d 100644
--- a/adminer/create.inc.php
+++ b/adminer/create.inc.php
@@ -40,14 +40,14 @@ if ($_POST && !$error && !$_POST["add"] && !$_POST["drop_col"] && !$_POST["up"]
 			$type_field = (isset($types[$field["type"]]) ? $field : $referencable_primary[$foreign_keys[$field["type"]]]);
 			if ($field["field"] != "") {
 				if ($type_field) {
+					if (!$field["has_default"]) {
+						$field["default"] = null;
+					}
 					$default = eregi_replace(" *on update CURRENT_TIMESTAMP", "", $field["default"]);
 					if ($default != $field["default"]) { // preg_replace $count is available since PHP 5.1.0
 						$field["on_update"] = "CURRENT_TIMESTAMP";
 						$field["default"] = $default;
 					}
-					if (!$field["has_default"]) {
-						$field["default"] = null;
-					}
 					$process_field = process_field($field, $type_field);
 					$auto_increment = ($key == $_POST["auto_increment_col"]);
 					if ($process_field != process_field($orig_field, $orig_field) || $orig_field["auto_increment"] != $auto_increment) {
diff --git a/adminer/static/editing.js b/adminer/static/editing.js
index f38dad78..cadc3aa1 100644
--- a/adminer/static/editing.js
+++ b/adminer/static/editing.js
@@ -200,6 +200,9 @@ function editingTypeChange(type) {
 		)) {
 			el.value = '';
 		}
+		if (lastType == 'timestamp' && el.name == name + '[has_default]' && /timestamp/i.test(formField(type.form, name + '[default]').value)) {
+			el.checked = false;
+		}
 		if (el.name == name + '[collation]') {
 			el.className = (/(char|text|enum|set)$/.test(text) ? '' : 'hidden');
 		}