diff --git a/pkgs/development/python-modules/pygatt/default.nix b/pkgs/development/python-modules/pygatt/default.nix
index 9d596e17236e..8d6f67a4c751 100644
--- a/pkgs/development/python-modules/pygatt/default.nix
+++ b/pkgs/development/python-modules/pygatt/default.nix
@@ -22,15 +22,19 @@ buildPythonPackage rec {
   };
 
   propagatedBuildInputs = [
-    pexpect
     pyserial
   ];
 
+  passthru.extras-require.GATTTOOL = [
+    pexpect
+  ];
+
   checkInputs = [
     mock
     nose
     pytestCheckHook
-  ];
+  ]
+  ++ passthru.extras-require.GATTTOOL;
 
   postPatch = ''
     # Not support for Python < 3.4