diff --git a/postgres-appliance/major_upgrade/pg_upgrade.py b/postgres-appliance/major_upgrade/pg_upgrade.py
index 3a0241bd..ad1563e8 100644
--- a/postgres-appliance/major_upgrade/pg_upgrade.py
+++ b/postgres-appliance/major_upgrade/pg_upgrade.py
@@ -204,8 +204,9 @@ def pg_upgrade(self, check=False):
     def prepare_new_pgdata(self, version):
         from spilo_commons import append_extensions
 
+        locale = self.query("SELECT datcollate FROM pg_database WHERE datname='template1';")[0][0]
         encoding = self.query('SHOW server_encoding')[0][0]
-        initdb_config = [{'encoding': encoding}]
+        initdb_config = [{'locale': locale}, {'encoding': encoding}]
         if self.query("SELECT current_setting('data_checksums')::bool")[0][0]:
             initdb_config.append('data-checksums')