diff --git a/altera/onehot_to_bin.v b/altera/onehot_to_bin.v
index 0c52e8e..dc4f03a 100755
--- a/altera/onehot_to_bin.v
+++ b/altera/onehot_to_bin.v
@@ -1,3 +1,4 @@
+`timescale 1ns / 1ps
 // Copyright 2007 Altera Corporation. All rights reserved.
 // Altera products are protected under numerous U.S. and foreign patents,
 // maskwork rights, copyrights and other intellectual property laws.