diff --git a/README.md b/README.md
index 7e9c07e..359c47c 100644
--- a/README.md
+++ b/README.md
@@ -140,7 +140,7 @@ tested. Additionally, the `--review` flag can be used to
 initiate a run of [nixpkgs-review](https://github.com/Mic92/nixpkgs-review), which will ensure all
 dependent packages can be built. In order to ensure consistent
 formatting, the `--format` flag will invoke
-[nixpkgs-fmt](https://github.com/nix-community/nixpkgs-fmt).
+[nixfmt](https://github.com/NixOS/nixfmt).
 
 ```console
 # Also runs nix-build
diff --git a/default.nix b/default.nix
index ea3f7d7..893382c 100644
--- a/default.nix
+++ b/default.nix
@@ -21,7 +21,7 @@ pkgs.python311.pkgs.buildPythonApplication {
   makeWrapperArgs = [
     "--prefix PATH"
     ":"
-    (pkgs.lib.makeBinPath [ pkgs.nixVersions.stable or pkgs.nix_2_4 pkgs.nixpkgs-review pkgs.nix-prefetch-git ])
+    (pkgs.lib.makeBinPath [ pkgs.nixVersions.stable or pkgs.nix_2_4 pkgs.nixpkgs-review pkgs.nix-prefetch-git pkgs.nixfmt-rfc-style ])
   ];
   shellHook = ''
     # workaround because `python setup.py develop` breaks for me
diff --git a/nix_update/__init__.py b/nix_update/__init__.py
index 32cfaaf..b626d46 100644
--- a/nix_update/__init__.py
+++ b/nix_update/__init__.py
@@ -31,7 +31,7 @@ def parse_args(args: list[str]) -> Options:
     parser.add_argument(
         "--review", action="store_true", help="Run `nixpkgs-review wip`"
     )
-    parser.add_argument("--format", action="store_true", help="Run `nixpkgs-fmt`")
+    parser.add_argument("--format", action="store_true", help="Run `nixfmt`")
     parser.add_argument(
         "--commit", action="store_true", help="Commit the updated package"
     )
@@ -326,7 +326,7 @@ def main(args: list[str] = sys.argv[1:]) -> None:
             nixpkgs_review()
 
     if options.format:
-        run(["nixpkgs-fmt", package.filename], stdout=None)
+        run(["nixfmt", package.filename], stdout=None)
 
     if options.commit:
         assert git_dir is not None
diff --git a/nix_update/version/__init__.py b/nix_update/version/__init__.py
index 995fa5a..699b65a 100644
--- a/nix_update/version/__init__.py
+++ b/nix_update/version/__init__.py
@@ -27,8 +27,7 @@ from .version import Version, VersionPreference
 
 
 class SnapshotFetcher(Protocol):
-    def __call__(self, url: ParseResult, branch: str) -> list[Version]:
-        ...
+    def __call__(self, url: ParseResult, branch: str) -> list[Version]: ...
 
 
 fetchers: list[Callable[[ParseResult], list[Version]]] = [