diff --git a/lib/Api/AccountApi.php b/lib/Api/AccountApi.php
index e7343c5..10827b0 100644
--- a/lib/Api/AccountApi.php
+++ b/lib/Api/AccountApi.php
@@ -2568,9 +2568,8 @@ protected function deleteAccountTagsRequest($accountId, $xKillbillCreatedBy, $ta
 
         // query params
         if (is_array($tagDef)) {
-            $tagDef = ObjectSerializer::serializeCollection($tagDef, /*'multi'*/'csv', true);
-        }
-        if ($tagDef !== null) {
+            $queryParams['tagDef'] = $tagDef;
+        } elseif ($tagDef !== null) {
             $queryParams['tagDef'] = ObjectSerializer::toQueryValue($tagDef);
         }
         // header params