diff --git a/src/program/migrations/0095_add_eventsession_constraint_and_missing_migrations.py b/src/program/migrations/0095_add_eventsession_constraint_and_missing_migrations.py
index 36112bae..41b9dafb 100644
--- a/src/program/migrations/0095_add_eventsession_constraint_and_missing_migrations.py
+++ b/src/program/migrations/0095_add_eventsession_constraint_and_missing_migrations.py
@@ -1,4 +1,4 @@
-# Generated by Django 3.0.3 on 2020-06-22 00:06
+# Generated by Django 3.0.3 on 2020-06-22 08:51
 
 import django.contrib.postgres.constraints
 from django.db import migrations, models
@@ -11,6 +11,10 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
+        migrations.RemoveConstraint(
+            model_name="eventsession",
+            name="prevent_event_session_event_type_event_location_overlaps",
+        ),
         migrations.AlterField(
             model_name="event",
             name="duration_minutes",
@@ -32,8 +36,21 @@ class Migration(migrations.Migration):
             model_name="eventsession",
             constraint=django.contrib.postgres.constraints.ExclusionConstraint(
                 expressions=[
+                    ("when", "&&"),
                     ("event_location", "="),
                     ("event_type", "="),
+                    ("event_duration_minutes", "="),
+                ],
+                name="prevent_event_session_event_type_event_location_overlaps",
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name="eventsession",
+            constraint=django.contrib.postgres.constraints.ExclusionConstraint(
+                expressions=[
+                    ("event_location", "="),
+                    ("event_type", "="),
+                    ("event_duration_minutes", "="),
                     ("when", "-|-"),
                 ],
                 name="prevent_adjacent_eventsessions",
diff --git a/src/program/models.py b/src/program/models.py
index 30b64fa3..ace17289 100644
--- a/src/program/models.py
+++ b/src/program/models.py
@@ -833,21 +833,23 @@ class EventSession(CampRelatedModel):
     class Meta:
         ordering = ["when", "event_type", "event_location"]
         constraints = [
-            # We do not want overlapping sessions for the same EventType/EventLocation combo.
+            # We do not want overlapping sessions for the same EventType/EventLocation/duration combo.
             ExclusionConstraint(
                 name="prevent_event_session_event_type_event_location_overlaps",
                 expressions=[
                     ("when", RangeOperators.OVERLAPS),
                     ("event_location", RangeOperators.EQUAL),
                     ("event_type", RangeOperators.EQUAL),
+                    ("event_duration_minutes", RangeOperators.EQUAL),
                 ],
             ),
-            # we do not want adjacent sessions for the same type and location
+            # we do not want adjacent sessions for the same type and location and duration
             ExclusionConstraint(
                 name="prevent_adjacent_eventsessions",
                 expressions=[
                     ("event_location", RangeOperators.EQUAL),
                     ("event_type", RangeOperators.EQUAL),
+                    ("event_duration_minutes", RangeOperators.EQUAL),
                     ("when", RangeOperators.ADJACENT_TO),
                 ],
             ),