diff --git a/.gitignore b/.gitignore
index 3177f76..3b47f9c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -39,3 +39,4 @@ CPLD/LCMXO*/impl1/*
 !CPLD/LCMXO*/impl1/*.srr
 !CPLD/LCMXO*/impl1/*.twr
 !CPLD/LCMXO*/impl1/*.tw1
+*.bak