diff --git a/.hgignore b/.hgignore
index 28623a7..2375ef1 100644
--- a/.hgignore
+++ b/.hgignore
@@ -13,6 +13,7 @@ autom4te.cache
 config.log
 config.status
 include/setup.h
+include/serno.h
 libratbox/include/libratbox_config.h
 libratbox/include/librb-config.h
 libratbox/include/stamp-h1