diff --git a/Modules/BookingManager/Objects/class.ilBookingObjectsTableGUI.php b/Modules/BookingManager/Objects/class.ilBookingObjectsTableGUI.php
index fa546b8ca946..7f8033e9b5f5 100644
--- a/Modules/BookingManager/Objects/class.ilBookingObjectsTableGUI.php
+++ b/Modules/BookingManager/Objects/class.ilBookingObjectsTableGUI.php
@@ -360,7 +360,7 @@ protected function fillRow(array $a_set): void
         }
 
         if ($has_booking || $this->may_edit) {
-            if (trim($a_set['post_text']) || $a_set['post_file']) {
+            if (trim($a_set['post_text'] ?? "") || $a_set['post_file']) {
                 $items[] = $this->ui_factory->button()->shy(
                     $lng->txt('book_post_booking_information'),
                     $ilCtrl->getLinkTargetByClass("ilbookingprocessgui", 'displayPostInfo')