diff --git a/init.d/lo.iface b/init.d/lo.iface
index 2ad1484..a62c25a 100755
--- a/init.d/lo.iface
+++ b/init.d/lo.iface
@@ -9,8 +9,8 @@ wait_for_iface() {
 	local iface="$1" timer='0' timeout='6'
 
 	until [[ "ip link show $iface up" ]]; do
-		[[ "$timer" -ge "$timeout" ]] && { return 1; }
-		timer=$[timer+1]
+		(( timer >= timeout )) && { return 1; }
+		(( timer++ ))
 	done
 }