diff --git a/src/Listener/ViewListener.php b/src/Listener/ViewListener.php
index 33e4a20..5b4df09 100644
--- a/src/Listener/ViewListener.php
+++ b/src/Listener/ViewListener.php
@@ -606,9 +606,9 @@ protected function _associations(array $whitelist = []): array
      *
      * If no value can be found, NULL is returned
      *
-     * @return array|string
+     * @return array|string|null
      */
-    protected function _primaryKeyValue(): array|string
+    protected function _primaryKeyValue(): array|string|null
     {
         $fields = (array)$this->_model()->getPrimaryKey();
         $values = [];