diff --git a/pkgs/development/python-modules/pytest-raisesregexp/default.nix b/pkgs/development/python-modules/pytest-raisesregexp/default.nix
new file mode 100644
index 00000000000..48572936433
--- /dev/null
+++ b/pkgs/development/python-modules/pytest-raisesregexp/default.nix
@@ -0,0 +1,26 @@
+{ stdenv, buildPythonPackage, fetchPypi
+, py, pytest }:
+
+buildPythonPackage rec {
+  pname = "pytest-raisesregexp";
+  version = "2.0";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0q8yby4g3il86rp7rhk89792wm17cykzsqcwbxpbbyal3an8mphg";
+  };
+
+  buildInputs = [ py pytest ];
+
+  # https://github.com/kissgyorgy/pytest-raisesregexp/pull/3
+  prePatch = ''
+    sed -i '3i\import io' setup.py
+    substituteInPlace setup.py --replace "long_description=open('README.rst').read()," "long_description=io.open('README.rst', encoding='utf-8').read(),"
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Simple pytest plugin to look for regex in Exceptions";
+    homepage = https://github.com/Walkman/pytest_raisesregexp;
+    license = with licenses; [ mit ];
+  };
+}
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index a6e09ba9ff4..1082faa838d 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -1944,29 +1944,7 @@ in {
 
   pytest-pep257 = callPackage ../development/python-modules/pytest-pep257 { };
 
-  pytest-raisesregexp = buildPythonPackage rec {
-    name = "pytest-raisesregexp-${version}";
-    version = "2.0";
-
-    src = pkgs.fetchurl {
-      url = "mirror://pypi/p/pytest-raisesregexp/${name}.tar.gz";
-      sha256 = "0fde8aac1a54f9b56e5f9c61fda76727542ed24968c27c6e3688c6f1885f1e61";
-    };
-
-    buildInputs = with self; [ py pytest ];
-
-    # https://github.com/kissgyorgy/pytest-raisesregexp/pull/3
-    prePatch = ''
-      sed -i '3i\import io' setup.py
-      substituteInPlace setup.py --replace "long_description=open('README.rst').read()," "long_description=io.open('README.rst', encoding='utf-8').read(),"
-    '';
-
-    meta = {
-      description = "Simple pytest plugin to look for regex in Exceptions";
-      homepage = https://github.com/Walkman/pytest_raisesregexp;
-      license = with licenses; [ mit ];
-    };
-  };
+  pytest-raisesregexp = callPackage ../development/python-modules/pytest-raisesregexp { };
 
   pytestrunner = callPackage ../development/python-modules/pytestrunner { };