diff --git a/Source/BPBIOS/.gitignore b/Source/BPBIOS/.gitignore
index d0e0dcfa..e1d7a6cb 100644
--- a/Source/BPBIOS/.gitignore
+++ b/Source/BPBIOS/.gitignore
@@ -1,5 +1,6 @@
 *.prn
 *.rel
 *.img
+bpsys.bak
 bpsys.dat
 def-ww.lib