diff --git a/pkgs/development/python-modules/whichcraft/default.nix b/pkgs/development/python-modules/whichcraft/default.nix
index c02114735ba6..89be87e18491 100644
--- a/pkgs/development/python-modules/whichcraft/default.nix
+++ b/pkgs/development/python-modules/whichcraft/default.nix
@@ -11,6 +11,10 @@ buildPythonPackage rec {
 
   checkInputs = [ pytest ];
 
+  checkPhase = ''
+    py.test
+  '';
+
   meta = with lib; {
     homepage = https://github.com/pydanny/whichcraft;
     description = "Cross-platform cross-python shutil.which functionality";