diff --git a/test/functional/gantts_controller_test.rb b/test/functional/gantts_controller_test.rb
index a7a7231f6..d89ae52db 100644
--- a/test/functional/gantts_controller_test.rb
+++ b/test/functional/gantts_controller_test.rb
@@ -150,6 +150,7 @@ class GanttsControllerTest < Redmine::ControllerTest
       :show,
       :params => {
         :project_id => 1,
+        :months => 1,
         :format => 'pdf'
       }
     )