diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index ff02c69..94ef61c 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -919,6 +919,10 @@
             finally:
                 tar.close()
 
+            # Verify that filter is a keyword-only argument
+            with self.assertRaises(TypeError):
+                tar.add(tempdir, "empty_dir", True, None, filter)
+
             tar = tarfile.open(tmpname, "r")
             try:
                 for tarinfo in tar: