diff --git a/shells/nixos-config.nix b/shells/nixos-config.nix
index bbf0ce81..0b0e176c 100644
--- a/shells/nixos-config.nix
+++ b/shells/nixos-config.nix
@@ -11,7 +11,7 @@
       name = "fetchpatch";
       category = "general commands";
       help = "Fetch a patch from a nixpkgs PR by its ID";
-      command = "curl -L https://github.com/NixOS/nixpkgs/pull/$1.patch -o $PRJ_ROOT/patches/$1.patch";
+      command = "curl -L https://github.com/NixOS/nixpkgs/pull/$1.diff -o $PRJ_ROOT/patches/$1.patch";
     }
   ];
   packages = [