diff --git a/src/Traits/Getter.php b/src/Traits/Getter.php
index 4c616e3..cd2ce95 100644
--- a/src/Traits/Getter.php
+++ b/src/Traits/Getter.php
@@ -63,7 +63,7 @@ trait Getter
      *
      * @return bool
      */
-    final public function __isset(string $property)
+    final public function __isset(string $property): bool
     {
         return !empty($this->__get($property));
     }