diff --git a/scripts/upgrade b/scripts/upgrade
index 1a4d3de..165ec36 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -100,7 +100,8 @@ then
 	ynh_script_progression --message="Upgrading source files..."
 
 	# Download, check integrity, uncompress and patch the source from app.src
-	if [ `cd $final_path && git rev-parse --is-inside-work-tree` ]; then
+	if git -C "$final_path" rev-parse --is-inside-work-tree` >/dev/null 2>/dev/null
+	then
 		pushd "$final_path"
 			git fetch
 			git checkout tags/$version