diff --git a/zephyr/management/commands/populate_db.py b/zephyr/management/commands/populate_db.py
index 18eeb69184..f391894ef6 100644
--- a/zephyr/management/commands/populate_db.py
+++ b/zephyr/management/commands/populate_db.py
@@ -51,7 +51,7 @@ class Command(BaseCommand):
             return
 
         for klass in [Zephyr, ZephyrClass, UserProfile, User, Recipient,
-                      Realm, Subscription, Huddle]:
+                      Realm, Subscription, Huddle, UserMessage]:
             klass.objects.all().delete()
 
         # Create a test realm