diff --git a/src/yunohost/data_migrations/0009_migrate_to_apps_json.py b/src/yunohost/data_migrations/0009_migrate_to_apps_json.py
index 8c81746d9..4f4baa5bd 100644
--- a/src/yunohost/data_migrations/0009_migrate_to_apps_json.py
+++ b/src/yunohost/data_migrations/0009_migrate_to_apps_json.py
@@ -18,7 +18,7 @@ class MyMigration(Migration):
     def migrate(self):
 
         # Backup current app list json
-        os.system("cp %s %s") % (APPSLISTS_JSON, APPSLISTS_BACKUP)
+        os.system("cp %s %s" % (APPSLISTS_JSON, APPSLISTS_BACKUP))
 
         # Remove all the deprecated lists
         lists_to_remove = [
@@ -39,4 +39,4 @@ class MyMigration(Migration):
     def backward(self):
 
         if os.path.exists(APPSLISTS_BACKUP):
-            os.system("cp %s %s") % (APPSLISTS_BACKUP, APPSLISTS_JSON)
+            os.system("cp %s %s" % (APPSLISTS_BACKUP, APPSLISTS_JSON))