diff --git a/src/python/grpcio_tests/tests_aio/unit/metadata_test.py b/src/python/grpcio_tests/tests_aio/unit/metadata_test.py
index 8a4ecd2fec6..17a9d1a0ecf 100644
--- a/src/python/grpcio_tests/tests_aio/unit/metadata_test.py
+++ b/src/python/grpcio_tests/tests_aio/unit/metadata_test.py
@@ -58,6 +58,14 @@ _INVALID_METADATA_TEST_CASES = (
         TypeError,
         (('normal', object()),),
     ),
+    (
+        TypeError,
+        object(),
+    ),
+    (
+        TypeError,
+        (object(),),
+    ),
 )