diff --git a/zerver/tests/test_events.py b/zerver/tests/test_events.py
index 9914eb3830..4e8d0205a0 100644
--- a/zerver/tests/test_events.py
+++ b/zerver/tests/test_events.py
@@ -79,6 +79,7 @@ from zerver.lib.actions import (
     do_update_outgoing_webhook_service,
     do_update_pointer,
     do_update_user_presence,
+    get_typing_user_profiles,
     log_event,
     lookup_default_stream_groups,
     notify_attachment_update,
@@ -912,6 +913,25 @@ class EventsRegisterTest(ZulipTestCase):
         error = schema_checker('events[0]', events[0])
         self.assert_on_error(error)
 
+    def test_get_typing_user_profiles(self) -> None:
+        """
+        Make sure we properly assert failures for recipient types that should not
+        get typing... notifications.
+        """
+
+        sender_profile = self.example_user('cordelia')
+        stream = get_stream('Rome', sender_profile.realm)
+
+        # Test stream
+        with self.assertRaisesRegex(ValueError, 'not supported for streams'):
+            recipient = Recipient.objects.get(type_id=stream.id, type=Recipient.STREAM)
+            get_typing_user_profiles(recipient, sender_profile.id)
+
+        # Test some other recipient type
+        with self.assertRaisesRegex(ValueError, 'Bad recipient type'):
+            recipient = Recipient(type=999) # invalid type
+            get_typing_user_profiles(recipient, sender_profile.id)
+
     def test_custom_profile_fields_events(self) -> None:
         schema_checker = self.check_events_dict([
             ('type', equals('custom_profile_fields')),