diff --git a/scripts/upgrade b/scripts/upgrade
index dc67387..03578d9 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -4,7 +4,7 @@
 set -eu
 
 # Load common variables and functions
-source ./_common.sh
+source ./_common
 
 # Retrieve arguments
 domain=$(ynh_app_setting_get "$app" domain)