diff --git a/flake.nix b/flake.nix
index f000a10..2578283 100755
--- a/flake.nix
+++ b/flake.nix
@@ -53,6 +53,7 @@
 
           home-manager.nixosModules.home-manager
           {
+            home-manager.backupFileExtension = "backup";
             home-manager.useUserPackages = true;
             home-manager.extraSpecialArgs = {inherit inputs outputs username;};
             home-manager.users.${username} = {
@@ -75,6 +76,7 @@
 
           home-manager.nixosModules.home-manager
           {
+            home-manager.backupFileExtension = "backup";
             home-manager.useUserPackages = true;
             home-manager.extraSpecialArgs = {inherit inputs outputs username;};
             home-manager.users.${username} = {
@@ -93,6 +95,7 @@
 
           home-manager.nixosModules.home-manager
           {
+            home-manager.backupFileExtension = "backup";
             home-manager.useUserPackages = true;
             home-manager.extraSpecialArgs = {inherit inputs outputs username;};
             home-manager.users.${username} = {