diff --git a/pkgs/by-name/lu/luarocks-packages-updater/updater.py b/pkgs/by-name/lu/luarocks-packages-updater/updater.py
index c89600a55cfa..4aa7ea6b9db0 100755
--- a/pkgs/by-name/lu/luarocks-packages-updater/updater.py
+++ b/pkgs/by-name/lu/luarocks-packages-updater/updater.py
@@ -143,6 +143,9 @@ class LuaEditor(pluginupdate.Editor):
 
         print(f"updated {outfilename}")
 
+        # Format the generated file with nix fmt
+        subprocess.run(["nix", "fmt", outfilename], check=True)
+
     @property
     def attr_path(self):
         return "luaPackages"