diff --git a/htdocs/societe/card.php b/htdocs/societe/card.php
index 8eda5988f80..52921b28c80 100644
--- a/htdocs/societe/card.php
+++ b/htdocs/societe/card.php
@@ -562,12 +562,12 @@ if (empty($reshook)) {
 				} else {
 					if ($result == -3 && in_array('ErrorCustomerCodeAlreadyUsed', $object->errors)) {
 						$duplicate_code_error = true;
-						$object->code_client = null;
+						$object->code_client = '';
 					}
 
 					if ($result == -3 && in_array('ErrorSupplierCodeAlreadyUsed', $object->errors)) {
 						$duplicate_code_error = true;
-						$object->code_fournisseur = null;
+						$object->code_fournisseur = '';
 					}
 
 					if ($db->lasterrno() == 'DB_ERROR_RECORD_ALREADY_EXISTS') {	// TODO Sometime errors on duplicate on profid and not on code, so we must manage this case