diff --git a/htdocs/expedition/class/expedition.class.php b/htdocs/expedition/class/expedition.class.php
index 2350c570fbb..2a20981a423 100644
--- a/htdocs/expedition/class/expedition.class.php
+++ b/htdocs/expedition/class/expedition.class.php
@@ -1490,7 +1490,7 @@ class Expedition extends CommonObject
 
 		// Add a protection to refuse deleting if shipment has at least one delivery
 		$this->fetchObjectLinked($this->id, 'shipping', 0, 'delivery'); // Get deliveries linked to this shipment
-		if (count($this->linkedObjectsIds) > 0) {
+		if (isset($this->linkedObjectsIds['delivery']) && count($this->linkedObjectsIds['delivery']) > 0) {
 			$this->error = 'ErrorThereIsSomeDeliveries';
 			$error++;
 		}
@@ -1700,7 +1700,7 @@ class Expedition extends CommonObject
 
 		// Add a protection to refuse deleting if shipment has at least one delivery
 		$this->fetchObjectLinked($this->id, 'shipping', 0, 'delivery'); // Get deliveries linked to this shipment
-		if (count($this->linkedObjectsIds) > 0) {
+		if (isset($this->linkedObjectsIds['delivery']) && count($this->linkedObjectsIds['delivery']) > 0) {
 			$this->error = 'ErrorThereIsSomeDeliveries';
 			$error++;
 		}