diff --git a/htdocs/commande/list.php b/htdocs/commande/list.php
index 79bbf69e31c..122d5702797 100644
--- a/htdocs/commande/list.php
+++ b/htdocs/commande/list.php
@@ -2215,7 +2215,11 @@ if ($resql) {
 			if (!$i) {
 				$totalarray['pos'][$totalarray['nbfield']] = 'c.total_tva';
 			}
-			$totalarray['val']['c.total_tva'] += $obj->total_tva;
+			if (isset($totalarray['val']['c.total_tva'])) {
+				$totalarray['val']['c.total_tva'] += $obj->total_tva;
+			} else {
+				$totalarray['val']['c.total_tva'] = $obj->total_tva;
+			}
 		}
 
 		// Amount TTC / gross
@@ -2227,7 +2231,11 @@ if ($resql) {
 			if (!$i) {
 				$totalarray['pos'][$totalarray['nbfield']] = 'c.total_ttc';
 			}
-			$totalarray['val']['c.total_ttc'] += $obj->total_ttc;
+			if (isset($totalarray['val']['c.total_ttc'])) {
+				$totalarray['val']['c.total_ttc'] += $obj->total_ttc;
+			} else {
+				$totalarray['val']['c.total_ttc'] = $obj->total_ttc;
+			}
 		}
 
 		// Currency