diff --git a/src/Valitron/Validator.php b/src/Valitron/Validator.php
index 93c06be..5a4423c 100644
--- a/src/Valitron/Validator.php
+++ b/src/Valitron/Validator.php
@@ -1229,7 +1229,7 @@ class Validator
     /**
      * Convenience method to add a single validation rule
      *
-     * @param string|callback $rule
+     * @param string|callable $rule
      * @param array|string $fields
      * @return Validator
      * @throws \InvalidArgumentException