diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3fb3a52..986d6a6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
   `crateNameFromCargoToml`) if they are not specified
 * `mkCargoDerivation` now defaults to an empty `checkPhaseCargoCommand` if not
   specified
+* `cargoFmt` now delegates to `mkCargoDerivation` instead of `cargoBuild`
 
 ### Fixed
 * Installing binaries now uses the same version of cargo as was used to build
diff --git a/docs/API.md b/docs/API.md
index fbd6460..c6b3bd0 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -402,20 +402,18 @@ Create a derivation which will run a `cargo fmt` invocation in a cargo
 workspace.
 
 Except where noted below, all derivation attributes are delegated to
-`cargoBuild`, and can be used to influence its behavior.
+`mkCargoDerivation`, and can be used to influence its behavior.
+* `buildPhaseCargoCommand` will be set to run `cargo fmt` (in check mode) in the
+  workspace.
 * `cargoArtifacts` is disabled/cleared
-* `cargoBuildCommand` will be set to run `cargo fmt` in the workspace.
-* `cargoExtraArgs` will have `rustFmtExtraArgs` appended to it
-  - Default value: `""`
 * `cargoVendorDir` is disabled/cleared
-* `doCheck` is disabled
 * `pnameSuffix` will be set to `"-fmt"`
 
 #### Optional attributes
-* `rustFmtExtraArgs`: additional flags to be passed in the rustfmt invocation
-  - Default value: `""`
 * `cargoExtraArgs`: additional flags to be passed in the cargo invocation
   - Default value: `""`
+* `rustFmtExtraArgs`: additional flags to be passed in the rustfmt invocation
+  - Default value: `""`
 
 #### Native build dependencies
 The `rustfmt` package is automatically appended as a native build input to any
@@ -426,6 +424,7 @@ The following attributes will be removed before being lowered to
 `cargoBuild`. If you absolutely need these attributes present as
 environment variables during the build, you can bring them back via
 `.overrideAttrs`.
+* `cargoExtraArgs`
 * `rustFmtExtraArgs`
 
 ### `lib.cargoNextest`
diff --git a/lib/cargoFmt.nix b/lib/cargoFmt.nix
index eb478d9..9c0799b 100644
--- a/lib/cargoFmt.nix
+++ b/lib/cargoFmt.nix
@@ -1,4 +1,4 @@
-{ cargoBuild
+{ mkCargoDerivation
 , rustfmt
 }:
 
@@ -7,16 +7,17 @@
 , ...
 }@origArgs:
 let
-  args = builtins.removeAttrs origArgs [ "rustFmtExtraArgs" ];
+  args = builtins.removeAttrs origArgs [
+    "cargoExtraArgs"
+    "rustFmtExtraArgs"
+  ];
 in
-cargoBuild (args // {
+mkCargoDerivation (args // {
   cargoArtifacts = null;
   cargoVendorDir = null;
-  doCheck = false;
   pnameSuffix = "-fmt";
 
-  cargoBuildCommand = "cargo fmt";
-  cargoExtraArgs = "${cargoExtraArgs} -- --check ${rustFmtExtraArgs}";
+  buildPhaseCargoCommand = "cargo fmt ${cargoExtraArgs} -- --check ${rustFmtExtraArgs}";
 
   nativeBuildInputs = (args.nativeBuildInputs or [ ]) ++ [ rustfmt ];