diff --git a/validation/custom_constraint.rst b/validation/custom_constraint.rst
index 0dffa0fa29d..16a02c12894 100644
--- a/validation/custom_constraint.rst
+++ b/validation/custom_constraint.rst
@@ -660,7 +660,7 @@ class to simplify writing unit tests for your custom constraints::
                 ->assertRaised();
         }
 
-        public function provideInvalidConstraints(): iterable
+        public function provideInvalidConstraints(): \Generator
         {
             yield [new ContainsAlphanumeric(message: 'myMessage')];
             // ...