diff --git a/flight/core/FilteredCallable.php b/flight/core/FilteredCallable.php
index 00c99fc..9e686cd 100644
--- a/flight/core/FilteredCallable.php
+++ b/flight/core/FilteredCallable.php
@@ -9,8 +9,8 @@ use ReflectionFunction;
 use Throwable;
 
 /**
- * @template CallableWithoutFilters of Closure
- * @template Output of mixed
+ * @template CallableWithoutFilters of Closure = Closure
+ * @template Output = mixed
  */
 final class FilteredCallable
 {