diff --git a/.gitattributes b/.gitattributes
index b5040d3..1b7408c 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1 @@
-systems/x86_64-linux/mx/mailserver.nix text filter=rot8000
+systems/x86_64-linux/mx/mailserver.nix text filter=rot8000 required