diff --git a/Base/ActiveQueryInterface.php b/Base/ActiveQueryInterface.php
index ebde026..745d9fd 100644
--- a/Base/ActiveQueryInterface.php
+++ b/Base/ActiveQueryInterface.php
@@ -250,7 +250,7 @@ interface ActiveQueryInterface
      *
      * @return QueryTrait
      */
-    public function groupBy(string $name, string $having = NULL): QueryTrait;
+    public function groupBy(string $name, ?string $having = NULL): QueryTrait;
 
     /**
      * @param int $limit
@@ -267,4 +267,4 @@ interface ActiveQueryInterface
     public function offset(int $offset): QueryTrait;
 
 
-}
\ No newline at end of file
+}