diff --git a/htdocs/product/class/api_products.class.php b/htdocs/product/class/api_products.class.php
index 05bf0253519..e92950f5e2a 100644
--- a/htdocs/product/class/api_products.class.php
+++ b/htdocs/product/class/api_products.class.php
@@ -226,7 +226,7 @@ class Products extends DolibarrApi
 						$obj_ret[] = $this->_cleanObjectDatas($product_static);
 					}
 				} else {
-					$obj_ret[] = $obj;
+					$obj_ret[] = $obj->rowid;
 				}
 				$i++;
 			}