diff --git a/includes/Parameters.php b/includes/Parameters.php
index 05ca38c8e..6a4cfcab5 100644
--- a/includes/Parameters.php
+++ b/includes/Parameters.php
@@ -957,7 +957,7 @@ public function _titlematch( $option ) {
 	public function _nottitleregexp( $option ) {
 		$data = $this->getParameter( 'nottitle' );
 
-		if ( !is_array( $data['regexp'] ) ) {
+		if ( !$data || !is_array( $data['regexp'] ) ) {
 			$data['regexp'] = [];
 		}