diff --git a/stubs/CoreGenericIterators.phpstub b/stubs/CoreGenericIterators.phpstub
index f74749b7d86..f4432d23aa6 100644
--- a/stubs/CoreGenericIterators.phpstub
+++ b/stubs/CoreGenericIterators.phpstub
@@ -358,7 +358,7 @@ class CachingIterator extends IteratorIterator implements OuterIterator , ArrayA
 
     /**
      * @param TIterator $iterator
-     * @param int-mask<1,2,4,8,16,256> $flags
+     * @param int-mask-of<self::*> $flags
      */
     public function __construct(Iterator $iterator, int $flags = self::CALL_TOSTRING) {}