diff --git a/src/program/migrations/0087_fk_and_related_name_underscores.py b/src/program/migrations/0087_fk_and_related_name_underscores.py
index 37f0e3e2..2609b824 100644
--- a/src/program/migrations/0087_fk_and_related_name_underscores.py
+++ b/src/program/migrations/0087_fk_and_related_name_underscores.py
@@ -45,6 +45,7 @@ class Migration(migrations.Migration):
             name="duration_minutes",
             field=models.PositiveIntegerField(
                 blank=True,
+                null=True,
                 default=None,
                 help_text="The duration of this event in minutes. Leave blank to use the default from the event_type.",
             ),