diff --git a/pkgs/development/python-modules/pytools/default.nix b/pkgs/development/python-modules/pytools/default.nix
new file mode 100644
index 000000000000..afdbed8ea0fb
--- /dev/null
+++ b/pkgs/development/python-modules/pytools/default.nix
@@ -0,0 +1,41 @@
+{ lib
+, buildPythonPackage
+, fetchFromGitHub
+, decorator
+, appdirs
+, six
+, numpy
+, pytest
+}:
+
+buildPythonPackage rec {
+  pname = "pytools";
+  version = "2017.4";
+
+  src = fetchFromGitHub {
+    owner = "inducer";
+    repo = "pytools";
+    rev = "8078e74265bb5a3c9676c698595ab5450cd2bfe7";
+    sha256 = "17q61l79fcxkj5jxg3fnymi652sdjp5s6kpsabgxp22kma9crr28";
+  };
+
+  checkInputs = [ pytest ];
+
+  propagatedBuildInputs = [
+    decorator
+    appdirs
+    six
+    numpy
+  ];
+
+  checkPhase = ''
+    py.test -k 'not test_persistent_dict'
+  '';
+
+  meta = {
+    homepage = https://github.com/inducer/pytools/;
+    description = "Miscellaneous Python lifesavers.";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ artuuge ];
+  };
+}
\ No newline at end of file
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 4eefa3a7ea8a..05d9e5a4c3e0 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -6789,37 +6789,7 @@ in {
 
   pysrt = callPackage ../development/python-modules/pysrt { };
 
-  pytools = buildPythonPackage rec {
-    name = "pytools-${version}";
-    version = "2017.4";
-
-    src = pkgs.fetchFromGitHub {
-      owner = "inducer";
-      repo = "pytools";
-      rev = "8078e74265bb5a3c9676c698595ab5450cd2bfe7";
-      sha256 = "17q61l79fcxkj5jxg3fnymi652sdjp5s6kpsabgxp22kma9crr28";
-    };
-
-    buildInputs = with self; [
-      decorator
-      appdirs
-      six
-      numpy
-      pytest
-    ];
-
-    checkPhase = ''
-      py.test -k 'not test_persistent_dict'
-    '';
-
-    meta = {
-      homepage = https://github.com/inducer/pytools/;
-      description = "Miscellaneous Python lifesavers.";
-      license = licenses.mit;
-      maintainers = with maintainers; [ artuuge ];
-    };
-
-  };
+  pytools = callPackage ../development/python-modules/pytools { };
 
   pytun = buildPythonPackage rec {
     name = "pytun-${version}";