diff --git a/pkgs/development/python-modules/pytest-mock/default.nix b/pkgs/development/python-modules/pytest-mock/default.nix
index 51ec2a1f4cb..6b852583c7e 100644
--- a/pkgs/development/python-modules/pytest-mock/default.nix
+++ b/pkgs/development/python-modules/pytest-mock/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildPythonPackage, fetchPypi, isPy3k, pytest, mock, setuptools_scm }:
+{ lib, buildPythonPackage, fetchPypi, fetchpatch, isPy3k, pytest, mock, setuptools_scm }:
 
 buildPythonPackage rec {
   pname = "pytest-mock";
@@ -9,6 +9,11 @@ buildPythonPackage rec {
     sha256 = "8ed6c9ac6b7565b226b4da2da48876c9198d76401ec8d9c5e4c69b45423e33f8";
   };
 
+  patches = fetchpatch {
+    url = "${meta.homepage}/pull/107.patch";
+    sha256 = "07p7ra6lilfv04wyxc855zmfwxvnpmi9s0v6vh5bx769cj9jwxck";
+  };
+
   propagatedBuildInputs = [ pytest ] ++ lib.optional (!isPy3k) mock;
   nativeBuildInputs = [ setuptools_scm ];