diff --git a/nixos/shared/default.nix b/nixos/shared/default.nix
index 100badc..ee1dff2 100644
--- a/nixos/shared/default.nix
+++ b/nixos/shared/default.nix
@@ -43,6 +43,8 @@
 
   console.catppuccin.enable = true;
 
+  home-manager.backupFileExtension = "backup";
+
   users.users.lillian = {
     isNormalUser = true;
     extraGroups = ["sudo" "networkmanager" "wheel" "vboxsf" "docker"];