diff --git a/pkgs/development/python-modules/fastjet/default.nix b/pkgs/development/python-modules/fastjet/default.nix
new file mode 100644
index 000000000000..d3e62027ae77
--- /dev/null
+++ b/pkgs/development/python-modules/fastjet/default.nix
@@ -0,0 +1,92 @@
+{
+  lib,
+  stdenv,
+  fetchPypi,
+  fetchurl,
+  buildPythonPackage,
+  pytestCheckHook,
+  pkgs,
+  awkward,
+  numpy,
+  pybind11,
+  python,
+  setuptools,
+  setuptools-scm,
+  vector,
+}:
+
+let
+  fastjet =
+    (pkgs.fastjet.override {
+      inherit python;
+      withPython = true;
+    }).overrideAttrs
+      (prev: {
+        postInstall =
+          (prev.postInstall or "")
+          + ''
+            mv "$out/${python.sitePackages}/"{fastjet.py,_fastjet_swig.py}
+          '';
+      });
+  fastjet-contrib = pkgs.fastjet-contrib.override {
+    inherit fastjet;
+  };
+in
+
+buildPythonPackage rec {
+  pname = "fastjet";
+  version = "3.4.2.1";
+  pyproject = true;
+
+  src = fetchPypi {
+    pname = "fastjet";
+    inherit version;
+    hash = "sha256-YlYJWCdwEBiG+koh1X2app1HinvktryisxP/C024g1k=";
+  };
+
+  # unvendor fastjet/fastjet-contrib
+  postPatch = ''
+    substituteInPlace setup.py \
+      --replace-fail 'cmdclass={"build_ext": FastJetBuild, "install": FastJetInstall},' "" \
+      --replace-fail 'str(OUTPUT / "include")' "" \
+      --replace-fail 'str(OUTPUT / "lib")' ""
+    for file in src/fastjet/*.py; do
+      substituteInPlace "$file" \
+        --replace-warn "fastjet._swig" "_fastjet_swig"
+    done
+    sed -i src/fastjet/_pyjet.py -e '1iimport _fastjet_swig'
+  '';
+
+  strictDeps = true;
+
+  build-system = [
+    setuptools
+    setuptools-scm
+  ];
+
+  dependencies = [
+    fastjet
+  ];
+
+  buildInputs = [
+    pybind11
+    fastjet-contrib
+  ];
+
+  nativeCheckInputs = [
+    pytestCheckHook
+    awkward
+    numpy
+    vector
+  ];
+
+  env.SETUPTOOLS_SCM_PRETEND_VERSION = version;
+
+  meta = {
+    description = "Jet-finding in the Scikit-HEP ecosystem";
+    homepage = "https://github.com/scikit-hep/fastjet";
+    changelog = "https://github.com/scikit-hep/fastjet/releases/tag/v${version}";
+    license = lib.licenses.bsd3;
+    maintainers = with lib.maintainers; [ veprbl ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index abac140b6209..868922729599 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -4492,10 +4492,7 @@ self: super: with self; {
 
   fastimport = callPackage ../development/python-modules/fastimport { };
 
-  fastjet = toPythonModule (pkgs.fastjet.override {
-    withPython = true;
-    inherit (self) python;
-  });
+  fastjet = callPackage ../development/python-modules/fastjet { };
 
   fastjsonschema = callPackage ../development/python-modules/fastjsonschema { };