diff --git a/zerver/tests/test_messages.py b/zerver/tests/test_messages.py
index 047c5a6a95..3596be0040 100644
--- a/zerver/tests/test_messages.py
+++ b/zerver/tests/test_messages.py
@@ -112,7 +112,7 @@ class TestCrossRealmPMs(ZulipTestCase):
         user1 = self.create_user(user1_email)
         user1a = self.create_user(user1a_email)
         user2 = self.create_user(user2_email)
-        self.create_user(user3_email)
+        user3 = self.create_user(user3_email)
         feedback_bot = self.create_user(feedback_email)
         support_bot = self.create_user(support_email)
 
@@ -138,6 +138,14 @@ class TestCrossRealmPMs(ZulipTestCase):
         self.send_message(user1_email, [support_email], Recipient.PERSONAL)
         assert_message_received(support_bot, user1)
 
+        # We have a loophole where I can send PMs to other users as long
+        # as I copy a cross-realm bot from the same realm.  In practice this
+        # not a bug, since our only cross-realm bots are on the zulip.com
+        # realm.
+        self.send_message(user1_email, [user3_email, support_email], Recipient.PERSONAL)
+        assert_message_received(user3, user1)
+        assert_message_received(support_bot, user1)
+
         # Users can't email two cross-realm bots at once. (This is just
         # an anomaly of the current implementation.)
         with assert_disallowed():