diff --git a/src/yunohost/data_migrations/0017_postgresql_9p6_to_11.py b/src/yunohost/data_migrations/0017_postgresql_9p6_to_11.py
index b81cbd8be..2f277443e 100644
--- a/src/yunohost/data_migrations/0017_postgresql_9p6_to_11.py
+++ b/src/yunohost/data_migrations/0017_postgresql_9p6_to_11.py
@@ -36,9 +36,9 @@ class MyMigration(Migration):
             raise YunohostError("migration_0017_not_enough_space", path="/var/lib/postgresql/")
 
         self.runcmd("systemctl stop postgresql")
-        self.runcmd("pg_dropcluster --stop 11 main || true")  # We do not trigger an exception if the command fails because that probably means cluster 11 doesn't exists, which is fine because it's created during the pg_upgradecluster)
-        self.runcmd("pg_upgradecluster -m upgrade 9.6 main")
-        self.runcmd("pg_dropcluster --stop 9.6 main")
+        self.runcmd("LC_ALL=C pg_dropcluster --stop 11 main || true")  # We do not trigger an exception if the command fails because that probably means cluster 11 doesn't exists, which is fine because it's created during the pg_upgradecluster)
+        self.runcmd("LC_ALL=C pg_upgradecluster -m upgrade 9.6 main")
+        self.runcmd("LC_ALL=C pg_dropcluster --stop 9.6 main")
         self.runcmd("systemctl start postgresql")
 
     def package_is_installed(self, package_name):