diff --git a/extension.driver.php b/extension.driver.php
index e56c635..6cbc902 100644
--- a/extension.driver.php
+++ b/extension.driver.php
@@ -29,7 +29,7 @@ public function install(){
 			return true;
 		}
 
-		public function update($previousVersion){
+		public function update($previousVersion = false){
 			if(version_compare($previousVersion, '0.9.4', '<')) {
 				Symphony::Database()->query('ALTER TABLE `tbl_fields_metakeys` ADD `delete_empty_keys` INT(1) NOT NULL DEFAULT \'1\';');
 				// Get all the fields that are meta-keys:
@@ -74,4 +74,4 @@ public static function appendAssets() {
 				Administration::instance()->Page->addScriptToHead(URL . '/extensions/field_metakeys/assets/field_metakeys.publish.js', 100, false);
 			}
 		}
-	}
\ No newline at end of file
+	}