diff --git a/pkg/icingadb/v1/user.go b/pkg/icingadb/v1/user.go
index 4bdf5b93..378da2ae 100644
--- a/pkg/icingadb/v1/user.go
+++ b/pkg/icingadb/v1/user.go
@@ -35,7 +35,7 @@ type UsergroupCustomvar struct {
 
 type UsergroupMember struct {
 	MemberMeta  `json:",inline"`
-	UserId      types.Binary `json:"object_id"`
+	UserId      types.Binary `json:"user_id"`
 	UsergroupId types.Binary `json:"group_id"`
 }