diff --git a/include/ws_functions/pwg.categories.php b/include/ws_functions/pwg.categories.php
index 734ef0401..5e16cef4d 100644
--- a/include/ws_functions/pwg.categories.php
+++ b/include/ws_functions/pwg.categories.php
@@ -22,6 +22,7 @@ function ws_categories_getImages($params, &$service)
 
   $images = array();
   $image_ids = array();
+  $total_images = 0;
 
   //------------------------------------------------- get the related categories
   $where_clauses = array();