diff --git a/scripts/upgrade b/scripts/upgrade
index c6d0d1d..8e5c51c 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -84,7 +84,7 @@ then
 	ynh_script_progression --message="Upgrading source files..." --weight=3
 
 	# Download, check integrity, uncompress and patch the source from app.src
-	ynh_setup_source --dest_dir="$final_path" --source_id="app.$architecture"
+	ynh_setup_source --dest_dir="$final_path" --source_id="app.$architecture" --keep="prometheus.yml"
 fi
 
 chmod 750 "$final_path"