diff --git a/src/Reader.php b/src/Reader.php
index 811acfce..7669ebbc 100644
--- a/src/Reader.php
+++ b/src/Reader.php
@@ -452,7 +452,7 @@ public function getRecordsAsObject(string $className, array $header = []): Itera
     /**
      * Returns the header to be used for iteration.
      *
-     * @param array<array-key, string|int> $header
+     * @param array<int|string> $header
      *
      * @throws SyntaxError If the header contains non unique column name
      *