diff --git a/tests/mocks.py b/tests/mocks.py
index 38f1583..3940bb0 100644
--- a/tests/mocks.py
+++ b/tests/mocks.py
@@ -75,7 +75,7 @@ class MockPopen(object):
         self.mock.returncode = 0
 
     def assert_call(self, cmd):
-        self.mock.popen.assert_any_call(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+        self.mock.popen.assert_any_call(shlex.split(cmd), env=mock.ANY, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
 
     def cleanup(self):
         self._patch.stop()