diff --git a/.gitignore b/.gitignore
index f784b30d80e..0b419963a3e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,3 +16,4 @@ data/
 /_maps/map_files/**/*.dmm.backup
 /nano/debug.html
 *.db
+stddef.dm