diff --git a/test/unit/lib/redmine/field_format/attachment_format_test.rb b/test/unit/lib/redmine/field_format/attachment_format_test.rb
index 159d2c540..9fbaa3211 100644
--- a/test/unit/lib/redmine/field_format/attachment_format_test.rb
+++ b/test/unit/lib/redmine/field_format/attachment_format_test.rb
@@ -25,6 +25,7 @@ class Redmine::AttachmentFieldFormatTest < ActionView::TestCase
   fixtures :users
 
   def setup
+    User.current = nil
     set_language_if_valid 'en'
     set_tmp_attachments_directory
   end