diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 94ce7f9ce7..4bdd4729e9 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -2321,39 +2321,40 @@ def do_change_stream_description(stream, new_description):
 
 def do_create_realm(string_id, name, restricted_to_domain=None,
                     invite_required=None, org_type=None):
-    # type: (Text, Text, Optional[bool], Optional[bool], Optional[int]) -> Tuple[Realm, bool]
-    realm = get_realm(string_id)
-    created = not realm
-    if created:
-        kwargs = {}  # type: Dict[str, Any]
-        if restricted_to_domain is not None:
-            kwargs['restricted_to_domain'] = restricted_to_domain
-        if invite_required is not None:
-            kwargs['invite_required'] = invite_required
-        if org_type is not None:
-            kwargs['org_type'] = org_type
-        realm = Realm(string_id=string_id, name=name, **kwargs)
-        realm.save()
+    # type: (Text, Text, Optional[bool], Optional[bool], Optional[int]) -> Realm
+    existing_realm = get_realm(string_id)
+    if existing_realm is not None:
+        raise AssertionError("Realm %s already exists!" % (string_id,))
 
-        # Create stream once Realm object has been saved
-        notifications_stream, _ = create_stream_if_needed(realm, Realm.DEFAULT_NOTIFICATION_STREAM_NAME)
-        realm.notifications_stream = notifications_stream
-        realm.save(update_fields=['notifications_stream'])
+    kwargs = {}  # type: Dict[str, Any]
+    if restricted_to_domain is not None:
+        kwargs['restricted_to_domain'] = restricted_to_domain
+    if invite_required is not None:
+        kwargs['invite_required'] = invite_required
+    if org_type is not None:
+        kwargs['org_type'] = org_type
+    realm = Realm(string_id=string_id, name=name, **kwargs)
+    realm.save()
 
-        # Log the event
-        log_event({"type": "realm_created",
-                   "string_id": string_id,
-                   "restricted_to_domain": restricted_to_domain,
-                   "invite_required": invite_required,
-                   "org_type": org_type})
+    # Create stream once Realm object has been saved
+    notifications_stream, _ = create_stream_if_needed(realm, Realm.DEFAULT_NOTIFICATION_STREAM_NAME)
+    realm.notifications_stream = notifications_stream
+    realm.save(update_fields=['notifications_stream'])
 
-        # Send a notification to the admin realm (if configured)
-        if settings.NEW_USER_BOT is not None:
-            signup_message = "Signups enabled"
-            admin_realm = get_system_bot(settings.NEW_USER_BOT).realm
-            internal_send_message(admin_realm, settings.NEW_USER_BOT, "stream",
-                                  "signups", string_id, signup_message)
-    return (realm, created)
+    # Log the event
+    log_event({"type": "realm_created",
+               "string_id": string_id,
+               "restricted_to_domain": restricted_to_domain,
+               "invite_required": invite_required,
+               "org_type": org_type})
+
+    # Send a notification to the admin realm (if configured)
+    if settings.NEW_USER_BOT is not None:
+        signup_message = "Signups enabled"
+        admin_realm = get_system_bot(settings.NEW_USER_BOT).realm
+        internal_send_message(admin_realm, settings.NEW_USER_BOT, "stream",
+                              "signups", string_id, signup_message)
+    return realm
 
 def do_change_notification_settings(user_profile, name, value, log=True):
     # type: (UserProfile, str, bool, bool) -> None
diff --git a/zerver/tests/test_realm_domains.py b/zerver/tests/test_realm_domains.py
index 3500daf6bd..f183e4820e 100644
--- a/zerver/tests/test_realm_domains.py
+++ b/zerver/tests/test_realm_domains.py
@@ -121,9 +121,9 @@ class RealmDomainTest(ZulipTestCase):
 
     def test_get_realm_by_email_domain(self):
         # type: () -> None
-        realm1, created = do_create_realm('testrealm1', 'Test Realm 1')
-        realm2, created = do_create_realm('testrealm2', 'Test Realm 2')
-        realm3, created = do_create_realm('testrealm3', 'Test Realm 3')
+        realm1 = do_create_realm('testrealm1', 'Test Realm 1')
+        realm2 = do_create_realm('testrealm2', 'Test Realm 2')
+        realm3 = do_create_realm('testrealm3', 'Test Realm 3')
 
         realm_domain_1 = RealmDomain.objects.create(realm=realm1, domain='test1.com', allow_subdomains=True)
         realm_domain_2 = RealmDomain.objects.create(realm=realm2, domain='test2.test1.com', allow_subdomains=False)
@@ -161,8 +161,8 @@ class RealmDomainTest(ZulipTestCase):
 
     def test_email_allowed_for_realm(self):
         # type: () -> None
-        realm1, created = do_create_realm('testrealm1', 'Test Realm 1', restricted_to_domain=True)
-        realm2, created = do_create_realm('testrealm2', 'Test Realm 2', restricted_to_domain=True)
+        realm1 = do_create_realm('testrealm1', 'Test Realm 1', restricted_to_domain=True)
+        realm2 = do_create_realm('testrealm2', 'Test Realm 2', restricted_to_domain=True)
 
         realm_domain = RealmDomain.objects.create(realm=realm1, domain='test1.com', allow_subdomains=False)
         RealmDomain.objects.create(realm=realm2, domain='test2.test1.com', allow_subdomains=True)
diff --git a/zerver/tests/test_subs.py b/zerver/tests/test_subs.py
index 777640db39..86f5475fc9 100644
--- a/zerver/tests/test_subs.py
+++ b/zerver/tests/test_subs.py
@@ -740,7 +740,7 @@ class DefaultStreamTest(ZulipTestCase):
 
     def test_set_default_streams(self):
         # type: () -> None
-        (realm, _) = do_create_realm("testrealm", "Test Realm")
+        realm = do_create_realm("testrealm", "Test Realm")
         stream_dict = {
             "apple": {"description": "A red fruit", "invite_only": False},
             "banana": {"description": "A yellow fruit", "invite_only": False},
@@ -757,7 +757,7 @@ class DefaultStreamTest(ZulipTestCase):
 
     def test_set_default_streams_no_notifications_stream(self):
         # type: () -> None
-        (realm, _) = do_create_realm("testrealm", "Test Realm")
+        realm = do_create_realm("testrealm", "Test Realm")
         realm.notifications_stream = None
         realm.save(update_fields=["notifications_stream"])
         stream_dict = {
@@ -1439,7 +1439,7 @@ class SubscriptionAPITest(ZulipTestCase):
         Calling POST /json/users/me/subscriptions in a new realm
         should notify with a proper new stream link
         """
-        (realm, _) = do_create_realm("testrealm", "Test Realm")
+        realm = do_create_realm("testrealm", "Test Realm")
 
         notifications_stream = Stream.objects.get(name='announce', realm=realm)
         realm.notifications_stream = notifications_stream
diff --git a/zerver/views/registration.py b/zerver/views/registration.py
index ab94ab312d..f26ca3bc6b 100644
--- a/zerver/views/registration.py
+++ b/zerver/views/registration.py
@@ -195,7 +195,7 @@ def accounts_register(request):
         if realm_creation:
             string_id = form.cleaned_data['realm_subdomain']
             realm_name = form.cleaned_data['realm_name']
-            realm = do_create_realm(string_id, realm_name)[0]
+            realm = do_create_realm(string_id, realm_name)
             setup_initial_streams(realm)
         assert(realm is not None)