diff --git a/src/DataGrid.php b/src/DataGrid.php
index ac72bbe9..ab3b69d2 100644
--- a/src/DataGrid.php
+++ b/src/DataGrid.php
@@ -2784,7 +2784,7 @@ public function getPerPage()
 		$per_page = $this->per_page ?: reset($items_per_page_list);
 
 		if (($per_page !== 'all' && !in_array((int) $this->per_page, $items_per_page_list, true))
-			|| ($per_page === 'all' && !in_array($this->per_page, $items_per_page_list, true))) {
+			|| ($per_page === 'all' && !array_key_exists($this->per_page, $items_per_page_list, true))) {
 			$per_page = reset($items_per_page_list);
 		}