diff --git a/common/lib/xmodule/xmodule/peer_grading_module.py b/common/lib/xmodule/xmodule/peer_grading_module.py
index c9fe618b10..cfe8667213 100644
--- a/common/lib/xmodule/xmodule/peer_grading_module.py
+++ b/common/lib/xmodule/xmodule/peer_grading_module.py
@@ -191,7 +191,8 @@ class PeerGradingModule(PeerGradingFields, XModule):
         if not self.use_for_single_location_local:
             return self.peer_grading()
         else:
-            return self.peer_grading_problem({'location': self.link_to_location})['html']
+            # b/c handle_ajax expects serialized data payload and directly calls peer_grading
+            return self.peer_grading_problem({'location': self.link_to_location.to_deprecated_string()})['html']
 
     def handle_ajax(self, dispatch, data):
         """
diff --git a/lms/djangoapps/open_ended_grading/views.py b/lms/djangoapps/open_ended_grading/views.py
index 508c07eac5..26c6bbe021 100644
--- a/lms/djangoapps/open_ended_grading/views.py
+++ b/lms/djangoapps/open_ended_grading/views.py
@@ -35,14 +35,14 @@ def _reverse_with_slash(url_name, course_key):
     @param course_id: The id of the course object (eg course.id).
     @returns: The reversed url with a trailing slash.
     """
-    course_id = course_key.to_deprecated_string()
-    ajax_url = _reverse_without_slash(url_name, course_id)
+    ajax_url = _reverse_without_slash(url_name, course_key)
     if not ajax_url.endswith('/'):
         ajax_url += '/'
     return ajax_url
 
 
-def _reverse_without_slash(url_name, course_id):
+def _reverse_without_slash(url_name, course_key):
+    course_id = course_key.to_deprecated_string()
     ajax_url = reverse(url_name, kwargs={'course_id': course_id})
     return ajax_url