diff --git a/common.nix b/common.nix
index 9f8780d..1ecca88 100644
--- a/common.nix
+++ b/common.nix
@@ -49,6 +49,7 @@
   # Home Manager #
   home-manager.useGlobalPkgs = true;
   home-manager.useUserPackages = true;
+  home-manager.backupFileExtension = "hm-bak";
   home-manager.extraSpecialArgs = { inherit inputs; };
   home-manager.users.fred = import ./home-manager/fred.nix;