diff --git a/pkgs/development/compilers/rust/rustfmt.nix b/pkgs/development/compilers/rust/rustfmt.nix
index e564cabd85e..d7bcb994313 100644
--- a/pkgs/development/compilers/rust/rustfmt.nix
+++ b/pkgs/development/compilers/rust/rustfmt.nix
@@ -1,8 +1,8 @@
-{ stdenv, rustPlatform, rustc, Security }:
+{ stdenv, rustPlatform, Security }:
 
 rustPlatform.buildRustPackage rec {
   name = "rustfmt-${version}";
-  inherit (rustc) version src;
+  inherit (rustPlatform.rust.rustc) version src;
 
   # the rust source tarball already has all the dependencies vendored, no need to fetch them again
   cargoVendorDir = "vendor";
@@ -14,70 +14,11 @@ rustPlatform.buildRustPackage rec {
   # As of 1.0.0 and rustc 1.30 rustfmt requires a nightly compiler
   RUSTC_BOOTSTRAP = 1;
 
-  # Without disabling the test the build fails with:
-  #
-  #   Compiling rustc_llvm v0.0.0 (/private/tmp/nix-build-rustfmt-1.36.0.drv-0/rustc-1.36.0-src/src/librustc_llvm)
-  #   ...
-  #   error: failed to run custom build command for `rustc_llvm v0.0.0
-  #     (/private/tmp/nix-build-rustfmt-1.36.0.drv-0/rustc-1.36.0-src/src/librustc_llvm)`
-  #
-  #   Caused by:
-  #     process didn't exit successfully:
-  #       `/private/tmp/nix-build-rustfmt-1.36.0.drv-0/rustc-1.36.0-src/target/debug/build/rustc_llvm-4d3eb1eff32fd46b/build-script-build` (exit code: 101)
-  #   --- stdout
-  #   cargo:rerun-if-env-changed=REAL_LIBRARY_PATH_VAR
-  #   cargo:rerun-if-env-changed=REAL_LIBRARY_PATH
-  #
-  #   --- stderr
-  #   thread 'main' panicked at 'REAL_LIBRARY_PATH_VAR', src/libcore/option.rs:1036:5
-  #   note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
-  #
-  # Setting the following:
-  #
-  #   # This mimics https://github.com/rust-lang/rust/blob/1.36.0/src/bootstrap/util.rs#L58:L70
-  #   REAL_LIBRARY_PATH_VAR =
-  #     if stdenv.isDarwin then "DYLD_LIBRARY_PATH"
-  #     else "LD_LIBRARY_PATH";
-  #
-  # Results in:
-  #
-  #   Compiling rustc_llvm v0.0.0 (/private/tmp/nix-build-rustfmt-1.36.0.drv-0/rustc-1.36.0-src/src/librustc_llvm)
-  #   ...
-  #   error: failed to run custom build command for `rustc_llvm v0.0.0 (/private/tmp/nix-build-rustfmt-1.36.0.drv-0/rustc-1.36.0-src/src/librustc_llvm)`
-  #
-  #   Caused by:
-  #     process didn't exit successfully: `/private/tmp/nix-build-rustfmt-1.36.0.drv-0/rustc-1.36.0-src/target/debug/build/rustc_llvm-4d3eb1eff32fd46b/build-script-build` (exit code: 1)
-  #   --- stdout
-  #   cargo:rerun-if-env-changed=REAL_LIBRARY_PATH_VAR
-  #   cargo:rerun-if-env-changed=REAL_LIBRARY_PATH
-  #   cargo:rerun-if-changed=llvm-config
-  #   cargo:rerun-if-env-changed=LLVM_CONFIG
-  #
-  #
-  #   failed to execute command: "llvm-config" "--version"
-  #   error: No such file or directory (os error 2)
-  #
-  # Adding `llvmSharedForBuild` to rustc's `passthru` and adding
-  # `rustc.llvmSharedForBuild` to the `buildInputs` fixes this but then the
-  # build fails lateron with:
-  #
-  #   Compiling rustc_llvm v0.0.0 (/private/tmp/nix-build-rustfmt-1.36.0.drv-0/rustc-1.36.0-src/src/librustc_llvm)
-  #   ...
-  #   error[E0658]: use of unstable library feature 'rustc_private': this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via `Cargo.toml` instead?
-  #    --> src/librustc_llvm/lib.rs:9:1
-  #     |
-  #   9 | extern crate rustc_cratesio_shim;
-  #     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-  #     |
-  #     = note: for more information, see https://github.com/rust-lang/rust/issues/27812
-  #     = help: add #![feature(rustc_private)] to the crate attributes to enable
-  #
-  #   error: aborting due to previous error
-  #
-  #   For more information about this error, try `rustc --explain E0658`.
-  #
-  #   error: Could not compile `rustc_llvm`.
-  doCheck = false;
+  # we run tests in debug mode so tests look for a debug build of
+  # rustfmt. Anyway this adds nearly no compilation time.
+  preCheck = ''
+    cargo build
+  '';
 
   meta = with stdenv.lib; {
     description = "A tool for formatting Rust code according to style guidelines";