diff --git a/src/Pinterest/Api.php b/src/Pinterest/Api.php
index 44cfcd9..d313edf 100644
--- a/src/Pinterest/Api.php
+++ b/src/Pinterest/Api.php
@@ -152,7 +152,7 @@ private function fetchPin(Request $request)
      * Fetch multiple boards and processes the response.
      *
      * @param Request    $request
-     * @param array|null $fields
+     * @param string[] $fields
      *
      * @throws RateLimitedReached
      *