diff --git a/pkgs/development/python-modules/sphinxcontrib-blockdiag/default.nix b/pkgs/development/python-modules/sphinxcontrib-blockdiag/default.nix
new file mode 100644
index 00000000000..1eeb40ddbc2
--- /dev/null
+++ b/pkgs/development/python-modules/sphinxcontrib-blockdiag/default.nix
@@ -0,0 +1,36 @@
+{ stdenv
+, buildPythonPackage
+, fetchPypi
+, python
+, mock
+, sphinx-testing
+, sphinx
+, blockdiag
+}:
+
+buildPythonPackage rec {
+  pname = "sphinxcontrib-blockdiag";
+  version = "1.5.5";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "1w7q2hhpzk159wd35hlbwkh80hnglqa475blcd9vjwpkv1kgkpvw";
+  };
+
+  buildInputs = [ mock sphinx-testing ];
+  propagatedBuildInputs = [ sphinx blockdiag ];
+
+  # Seems to look for files in the wrong dir
+  doCheck = false;
+  checkPhase = ''
+    ${python.interpreter} -m unittest discover -s tests
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Sphinx blockdiag extension";
+    homepage = "https://github.com/blockdiag/sphinxcontrib-blockdiag";
+    maintainers = with maintainers; [ nand0p ];
+    license = licenses.bsd2;
+  };
+
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 85b8f3993f9..b546ddd7ead 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -3878,31 +3878,7 @@ in {
 
   sphinxcontrib-bibtex = callPackage ../development/python-modules/sphinxcontrib-bibtex {};
 
-  sphinxcontrib-blockdiag = buildPythonPackage (rec {
-    name = "${pname}-${version}";
-    pname = "sphinxcontrib-blockdiag";
-    version = "1.5.5";
-    src = pkgs.fetchurl {
-      url = "mirror://pypi/s/${pname}/${name}.tar.gz";
-      sha256 = "1w7q2hhpzk159wd35hlbwkh80hnglqa475blcd9vjwpkv1kgkpvw";
-    };
-
-    buildInputs = with self; [ mock sphinx-testing ];
-    propagatedBuildInputs = with self; [ sphinx blockdiag ];
-
-    # Seems to look for files in the wrong dir
-    doCheck = false;
-    checkPhase = ''
-      ${python.interpreter} -m unittest discover -s tests
-    '';
-
-    meta = {
-      description = "Sphinx blockdiag extension";
-      homepage = "https://github.com/blockdiag/sphinxcontrib-blockdiag";
-      maintainers = with maintainers; [ nand0p ];
-      license = licenses.bsd2;
-    };
-  });
+  sphinxcontrib-blockdiag = callPackage ../development/python-modules/sphinxcontrib-blockdiag { };
 
   sphinxcontrib-openapi = buildPythonPackage (rec {
     name = "sphinxcontrib-openapi-0.3.0";