diff --git a/pkgs/development/python-modules/hypothesis.nix b/pkgs/development/python-modules/hypothesis.nix
index b9f95d1a031..cb0db6dc2e0 100644
--- a/pkgs/development/python-modules/hypothesis.nix
+++ b/pkgs/development/python-modules/hypothesis.nix
@@ -1,6 +1,6 @@
 { stdenv, buildPythonPackage, fetchFromGitHub, python
 , pythonOlder, pythonAtLeast, enum34
-, doCheck ? true, pytest, flake8, flaky
+, doCheck ? true, pytest, pytest_xdist, flake8, flaky
 }:
 buildPythonPackage rec {
   # http://hypothesis.readthedocs.org/en/latest/packaging.html
@@ -21,7 +21,7 @@ buildPythonPackage rec {
     sha256 = "1s911pd3y9hvk0hq2fr6i68dqv1ciagryhgp13wgyfqh8hz8j6zv";
   };
 
-  checkInputs = stdenv.lib.optionals doCheck [ pytest flake8 flaky ];
+  checkInputs = stdenv.lib.optionals doCheck [ pytest pytest_xdist flake8 flaky ];
   propagatedBuildInputs = stdenv.lib.optionals (pythonOlder "3.4") [ enum34 ];
 
   inherit doCheck;
diff --git a/pkgs/development/python-modules/ldap.nix b/pkgs/development/python-modules/ldap.nix
index e2625e2bfbf..3e715bbe419 100644
--- a/pkgs/development/python-modules/ldap.nix
+++ b/pkgs/development/python-modules/ldap.nix
@@ -1,4 +1,4 @@
-{ buildPythonPackage, isPy3k, fetchurl
+{ buildPythonPackage, isPy3k, fetchPypi
 , openldap, cyrus_sasl, openssl }:
 
 buildPythonPackage rec {
@@ -7,8 +7,8 @@ buildPythonPackage rec {
   name = "${pname}-${version}";
   disabled = isPy3k;
 
-  src = fetchurl {
-    url = "mirror://pypi/p/python-ldap/python-${name}.tar.gz";
+  src = fetchPypi {
+    inherit pname version;
     sha256 = "88bab69e519dd8bd83becbe36bd141c174b0fe309e84936cf1bae685b31be779";
   };
 
diff --git a/pkgs/development/python-modules/pylibmc/default.nix b/pkgs/development/python-modules/pylibmc/default.nix
index ff53e3d304f..7f57f17efeb 100644
--- a/pkgs/development/python-modules/pylibmc/default.nix
+++ b/pkgs/development/python-modules/pylibmc/default.nix
@@ -1,11 +1,11 @@
-{ buildPythonPackage, fetchurl, stdenv, libmemcached, zlib }:
+{ buildPythonPackage, fetchPypi, stdenv, libmemcached, zlib }:
 buildPythonPackage rec {
   version = "1.5.2";
   pname = "pylibmc";
   name = "${pname}-${version}";
 
-  src = fetchurl {
-    url = "https://pypi.python.org/packages/source/p/pylibmc/${name}.tar.gz";
+  src = fetchPypi {
+    inherit pname version;
     sha256 = "fc54e28a9f1b5b2ec0c030da29c7ad8a15c2755bd98aaa4142eaf419d5fabb33";
   };
 
diff --git a/pkgs/development/python-modules/pylint/default.nix b/pkgs/development/python-modules/pylint/default.nix
index 2922faafa7f..130aef60f97 100644
--- a/pkgs/development/python-modules/pylint/default.nix
+++ b/pkgs/development/python-modules/pylint/default.nix
@@ -1,5 +1,5 @@
 { stdenv, fetchurl, buildPythonPackage, python, astroid, isort,
-  pytest,  mccabe, configparser, backports_functools_lru_cache }:
+  pytest, pytestrunner,  mccabe, configparser, backports_functools_lru_cache }:
 
   buildPythonPackage rec {
     name = "${pname}-${version}";
@@ -11,7 +11,7 @@
       sha256 = "8b4a7ab6cf5062e40e2763c0b4a596020abada1d7304e369578b522e46a6264a";
     };
 
-    buildInputs = [ pytest mccabe configparser backports_functools_lru_cache ];
+    buildInputs = [ pytest pytestrunner mccabe configparser backports_functools_lru_cache ];
 
     propagatedBuildInputs = [ astroid isort ];