diff --git a/lms/djangoapps/django_comment_client/utils.py b/lms/djangoapps/django_comment_client/utils.py
index c3e2708f67..ed97c43113 100644
--- a/lms/djangoapps/django_comment_client/utils.py
+++ b/lms/djangoapps/django_comment_client/utils.py
@@ -129,6 +129,8 @@ def filter_unstarted_categories(category_map):
 def sort_map_entries(category_map):
     things = []
     for title, entry in category_map["entries"].items():
+        if entry["sort_key"] == None:
+            entry["sort_key"] = title
         things.append((title, entry))
     for title, category in category_map["subcategories"].items():
         things.append((title, category))
diff --git a/lms/templates/discussion/_filter_dropdown.html b/lms/templates/discussion/_filter_dropdown.html
index a51467eade..c09f295b11 100644
--- a/lms/templates/discussion/_filter_dropdown.html
+++ b/lms/templates/discussion/_filter_dropdown.html
@@ -2,7 +2,6 @@
 <%! import json %>
 
 <%def name="render_dropdown(map)">
-    ${map["children"].sort()}
     % for child in map["children"]:
         % if child in map["entries"]:
             ${render_entry(map["entries"], child)}