diff --git a/ietf/meeting/views.py b/ietf/meeting/views.py
index 8a028d435..5cffe9459 100644
--- a/ietf/meeting/views.py
+++ b/ietf/meeting/views.py
@@ -3621,7 +3621,8 @@ def organize_proceedings_sessions(sessions):
                 """
                 material_times = {}  # key is material, value is first timestamp it appeared
                 for s, mats in items:
-                    timestamp = s.official_timeslotassignment().timeslot.time
+                    tsa = s.official_timeslotassignment()
+                    timestamp = tsa.timeslot.time if tsa else None
                     if not isinstance(mats, list):
                         mats = [mats]
                     for mat in mats:
@@ -3640,7 +3641,7 @@ def organize_proceedings_sessions(sessions):
                 'group': group,
                 'name': sess_name,
                 'canceled': all_canceled,
-                # pass sessions instead of the materials here so session data (like time) is easily available
+                'has_materials': s.sessionpresentation_set.exists(),
                 'agendas': _format_materials((s, s.agenda()) for s in ss),
                 'minutes': _format_materials((s, s.minutes()) for s in ss),
                 'bluesheets': _format_materials((s, s.bluesheets()) for s in ss),
diff --git a/ietf/templates/meeting/proceedings.html b/ietf/templates/meeting/proceedings.html
index 6f3f2cda4..d4040ec8e 100644
--- a/ietf/templates/meeting/proceedings.html
+++ b/ietf/templates/meeting/proceedings.html
@@ -88,7 +88,7 @@
                     </tr>
                 </thead>
                 <tbody>
-                    {% for entry in not_meeting_groups %}{% if entry.sessions_with_materials %}
+                    {% for entry in not_meeting_groups %}{% if entry.has_materials %}
                         {% include "meeting/group_proceedings.html" with entry=entry meeting=meeting show_agenda=True only %}
                     {% endif %}{% endfor %}
                 </tbody>