diff --git a/tests/phpstan/configs/gradual-level6.neon b/tests/phpstan/configs/gradual-level6.neon
index 5e444dc7f8..f96da02efb 100644
--- a/tests/phpstan/configs/gradual-level6.neon
+++ b/tests/phpstan/configs/gradual-level6.neon
@@ -6,7 +6,7 @@ parameters:
 
 rules:
 	- PHPStan\Rules\Functions\MissingFunctionParameterTypehintRule
-	#- PHPStan\Rules\Functions\MissingFunctionReturnTypehintRule
+	- PHPStan\Rules\Functions\MissingFunctionReturnTypehintRule
 	#- PHPStan\Rules\Methods\MissingMethodParameterTypehintRule
 	#- PHPStan\Rules\Methods\MissingMethodReturnTypehintRule
 	- PHPStan\Rules\Properties\MissingPropertyTypehintRule