diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 8da1a4baf..8a00b21aa 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -18,7 +18,8 @@ import sys
 sys.dont_write_bytecode = True
 
 from synapse.storage import (
-    prepare_database, prepare_sqlite3_database, UpgradeDatabaseException,
+    prepare_database, prepare_sqlite3_database, are_all_users_on_domain,
+    UpgradeDatabaseException,
 )
 
 from synapse.server import HomeServer
@@ -242,10 +243,9 @@ class SynapseHomeServer(HomeServer):
             )
             logger.info("Metrics now running on 127.0.0.1 port %d", config.metrics_port)
 
-    @defer.inlineCallbacks
-    def post_startup_check(self):
-        all_users_native = yield self.get_datastore().are_all_users_on_domain(
-            self.hostname
+    def run_startup_checks(self, db_conn):
+        all_users_native = are_all_users_on_domain(
+            db_conn, self.hostname
         )
         if not all_users_native:
             sys.stderr.write(
@@ -254,9 +254,9 @@ class SynapseHomeServer(HomeServer):
                 "Found users in database not native to %s!\n"
                 "You cannot changed a synapse server_name after it's been configured\n"
                 "******************************************************\n"
-                "\n"
+                "\n" % (self.hostname,)
             )
-            reactor.stop()
+            sys.exit(1)
 
 
 def get_version_string():
@@ -392,6 +392,7 @@ def setup(config_options):
         with sqlite3.connect(db_name) as db_conn:
             prepare_sqlite3_database(db_conn)
             prepare_database(db_conn)
+            hs.run_startup_checks(db_conn)
     except UpgradeDatabaseException:
         sys.stderr.write(
             "\nFailed to upgrade database.\n"
@@ -416,8 +417,6 @@ def setup(config_options):
     hs.get_datastore().start_profiling()
     hs.get_replication_layer().start_get_pdu_cache()
 
-    reactor.callWhenRunning(hs.post_startup_check)
-
     return hs
 
 
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index f4dec7039..0c4744368 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -421,3 +421,13 @@ def prepare_sqlite3_database(db_conn):
                     " VALUES (?,?)",
                     (row[0], False)
                 )
+
+
+def are_all_users_on_domain(txn, domain):
+    sql = "SELECT COUNT(*) FROM users WHERE name NOT LIKE ?"
+    pat = "%:" + domain
+    cursor = txn.execute(sql, (pat,))
+    num_not_matching = cursor.fetchall()[0][0]
+    if num_not_matching == 0:
+        return True
+    return False
\ No newline at end of file
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 65ae58a39..f24154f14 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -144,21 +144,3 @@ class RegistrationStore(SQLBaseStore):
             return rows[0]
 
         raise StoreError(404, "Token not found.")
-
-    @defer.inlineCallbacks
-    def are_all_users_on_domain(self, domain):
-        res = yield self.runInteraction(
-            "are_all_users_on_domain",
-            self._are_all_users_on_domain_txn,
-            domain
-        )
-        defer.returnValue(res)
-
-    def _are_all_users_on_domain_txn(self, txn, domain):
-        sql = "SELECT COUNT(*) FROM users WHERE name NOT LIKE ?"
-        pat = "%:" + domain
-        cursor = txn.execute(sql, (pat,))
-        num_not_matching = cursor.fetchall()[0][0]
-        if num_not_matching == 0:
-            return True
-        return False