diff --git a/tests/test_sendgrid_backend.py b/tests/test_sendgrid_backend.py
index 498087d..c484660 100644
--- a/tests/test_sendgrid_backend.py
+++ b/tests/test_sendgrid_backend.py
@@ -21,7 +21,7 @@ from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharin
 from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin
 
 # noinspection PyUnresolvedReferences
-longtype = int if six.PY3 else long
+longtype = int if six.PY3 else long  # NOQA: F821
 
 
 @override_settings(EMAIL_BACKEND='anymail.backends.sendgrid.EmailBackend',
diff --git a/tests/test_sendgrid_v2_backend.py b/tests/test_sendgrid_v2_backend.py
index e2d6c7a..9eca867 100644
--- a/tests/test_sendgrid_v2_backend.py
+++ b/tests/test_sendgrid_v2_backend.py
@@ -21,7 +21,7 @@ from .mock_requests_backend import RequestsBackendMockAPITestCase, SessionSharin
 from .utils import sample_image_content, sample_image_path, SAMPLE_IMAGE_FILENAME, AnymailTestMixin
 
 # noinspection PyUnresolvedReferences
-longtype = int if six.PY3 else long
+longtype = int if six.PY3 else long  # NOQA: F821
 
 
 @override_settings(EMAIL_BACKEND='anymail.backends.sendgrid_v2.EmailBackend',