diff --git a/htdocs/product/class/html.formproduct.class.php b/htdocs/product/class/html.formproduct.class.php
index da10faa4f34..3c080f159f8 100644
--- a/htdocs/product/class/html.formproduct.class.php
+++ b/htdocs/product/class/html.formproduct.class.php
@@ -655,11 +655,13 @@ class FormProduct
 		}
 
 		foreach ($productIdArray as $productId) {
-			foreach ($this->cache_lot[$productId] as $id => $arraytypes) {
-				if (empty($fk_entrepot) || $fk_entrepot == $arraytypes['entrepot_id']) {
-					$label = $arraytypes['entrepot_label'].' - ';
-					$label .= $arraytypes['batch'];
-					$out .= '<option>'.$arraytypes['batch'].'</option>';
+			if (array_key_exists($productId, $this->cache_lot)) {
+				foreach ($this->cache_lot[$productId] as $id => $arraytypes) {
+					if (empty($fk_entrepot) || $fk_entrepot == $arraytypes['entrepot_id']) {
+						$label = $arraytypes['entrepot_label'] . ' - ';
+						$label .= $arraytypes['batch'];
+						$out .= '<option>' . $arraytypes['batch'] . '</option>';
+					}
 				}
 			}
 		}