diff --git a/src/PdoInterface.php b/src/PdoInterface.php
index bffb457e..fbd6357e 100644
--- a/src/PdoInterface.php
+++ b/src/PdoInterface.php
@@ -81,7 +81,7 @@ public function exec(string $statement): int|false;
      * @return mixed The value for the attribute.
      *
      */
-    public function getAttribute(int $attribute): mixed;
+    public function getAttribute(int $attribute): bool|int|string|array|null;
 
     /**
      *