diff --git a/pkgs/development/python-modules/whisper/default.nix b/pkgs/development/python-modules/whisper/default.nix
index 1fb9dd6da16a..0f8178e17f2b 100644
--- a/pkgs/development/python-modules/whisper/default.nix
+++ b/pkgs/development/python-modules/whisper/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, buildPythonPackage, fetchPypi, six }:
+{ stdenv, buildPythonPackage, fetchPypi, mock, six }:
 
 buildPythonPackage rec {
   pname = "whisper";
@@ -10,6 +10,7 @@ buildPythonPackage rec {
   };
 
   propagatedBuildInputs = [ six ];
+  checkInputs           = [ mock ];
 
   meta = with stdenv.lib; {
     homepage = http://graphite.wikidot.com/;