diff --git a/pkgs/development/python-modules/freezegun/default.nix b/pkgs/development/python-modules/freezegun/default.nix
index 926ad05156a..80a6f439de8 100644
--- a/pkgs/development/python-modules/freezegun/default.nix
+++ b/pkgs/development/python-modules/freezegun/default.nix
@@ -17,7 +17,7 @@ buildPythonPackage rec {
   };
 
   propagatedBuildInputs = [ dateutil six ];
-  buildInputs = [ mock nose ];
+  checkInputs = [ mock nose ];
 
   meta = with stdenv.lib; {
     description = "FreezeGun: Let your Python tests travel through time";