diff --git a/tox.ini b/tox.ini
index 60fba1ba..eaafb328 100644
--- a/tox.ini
+++ b/tox.ini
@@ -90,6 +90,8 @@ exclude_lines =
     if __name__ == '__main__':
     self.fail
     raise AssertionError
+    if TYPE_CHECKING:
+    assert_never
 
 [coverage:html]
 directory = parts/htmlcov