diff --git a/pkgs/development/python-modules/smbus-cffi/default.nix b/pkgs/development/python-modules/smbus-cffi/default.nix
index ffb22d1c4b4..79f177b1f94 100644
--- a/pkgs/development/python-modules/smbus-cffi/default.nix
+++ b/pkgs/development/python-modules/smbus-cffi/default.nix
@@ -2,6 +2,7 @@
 , buildPythonPackage
 , fetchPypi
 , cffi
+, py
 , pytestCheckHook
 , pyserial
 , fetchpatch
@@ -37,7 +38,7 @@ buildPythonPackage rec {
   # requires hardware access
   pytestFlagsArray = [ "--ignore=test/test_smbus_integration.py" ];
 
-  checkInputs = [ pytestCheckHook pyserial ];
+  checkInputs = [ py pytestCheckHook pyserial ];
 
   meta = with lib; {
     description = "Python module for SMBus access through Linux I2C /dev interface";