diff --git a/nominatim/clicmd/setup.py b/nominatim/clicmd/setup.py
index 49a9363d..626e3f2a 100644
--- a/nominatim/clicmd/setup.py
+++ b/nominatim/clicmd/setup.py
@@ -105,8 +105,7 @@ class SetupAll:
                                                         rouser=args.config.DATABASE_WEBUSER)
                 return 0
 
-            if not args.prepare_database or \
-                    args.continue_at == 'import-from-file':
+            if args.continue_at == 'import-from-file':
                 # Check if the correct plugins are installed
                 database_import.check_existing_database_plugins(args.config.get_libpq_dsn())
                 LOG.warning('Setting up country tables')
diff --git a/nominatim/db/connection.py b/nominatim/db/connection.py
index 51110f54..82801ae7 100644
--- a/nominatim/db/connection.py
+++ b/nominatim/db/connection.py
@@ -179,7 +179,7 @@ class Connection(psycopg2.extensions.connection):
         """ Return True if the hstore extension is loaded in the database.
         """
         with self.cursor() as cur:
-            cur.execute('SELECT extname FROM pg_extension WHERE extname = %s', (extension_name))
+            cur.execute('SELECT extname FROM pg_extension WHERE extname = %s', (extension_name, ))
             return cur.rowcount > 0