diff --git a/openassessment/xblock/test/test_load_static.py b/openassessment/xblock/test/test_load_static.py
index b265c30112..a0edd18726 100644
--- a/openassessment/xblock/test/test_load_static.py
+++ b/openassessment/xblock/test/test_load_static.py
@@ -53,9 +53,10 @@ def test_get_url_with_custom_static_url(self):
 
     @patch('pkg_resources.resource_string')
     def test_is_dev_server_url(self, resource_string):
+        # some unknown bug in python mock, need to call setUp() again
+        self.setUp()
         resource_string.return_value = None
         key_url = 'some_url.js'
-        print(LoadStatic._manifest)
         with patch('json.loads') as jsondata:
             manifest = {
                 'some_url.js': 'some_url.hash.js',