diff --git a/pkgs/development/python-modules/xvfbwrapper/default.nix b/pkgs/development/python-modules/xvfbwrapper/default.nix
index 0758baacff8..4ba9cd61d4c 100644
--- a/pkgs/development/python-modules/xvfbwrapper/default.nix
+++ b/pkgs/development/python-modules/xvfbwrapper/default.nix
@@ -2,6 +2,7 @@
 , buildPythonPackage
 , fetchPypi
 , xorgserver
+, mock
 }:
 
 buildPythonPackage rec {
@@ -14,6 +15,8 @@ buildPythonPackage rec {
   };
   propagatedBuildInputs = [ xorgserver ];
 
+  checkInputs = [ mock ];
+
   meta = with stdenv.lib; {
     description = "Run headless display inside X virtual framebuffer (Xvfb)";
     homepage = https://github.com/cgoldberg/xvfbwrapper;