diff --git a/flake.nix b/flake.nix
index f79317b..3eb17e6 100644
--- a/flake.nix
+++ b/flake.nix
@@ -26,6 +26,7 @@
       apps.nixos-diff = {
         type = "app";
         program = "${pkgs.writeShellScript "nixos-diff.sh" ''
+          ${pkgs.git}/bin/git pull --ff-only
           ${pkgs.nixos-rebuild}/bin/nixos-rebuild build
           ${pkgs.nvd}/bin/nvd diff /run/current-system ./result
         ''}";