diff --git a/zulip_bots/zulip_bots/lib.py b/zulip_bots/zulip_bots/lib.py
index 1911e58..f8dc626 100644
--- a/zulip_bots/zulip_bots/lib.py
+++ b/zulip_bots/zulip_bots/lib.py
@@ -268,7 +268,7 @@ def extract_query_without_mention(message: Dict[str, Any], client: ExternalBotHa
     return None
 
 
-def is_private_message_from_another_user(message_dict: Dict[str, Any], current_user_id: int) -> bool:
+def is_private_message_but_not_group_pm(message_dict: Dict[str, Any], current_user: ExternalBotHandler) -> bool:
     """
     Checks whether a message dict represents a PM from another user.
 
@@ -276,9 +276,11 @@ def is_private_message_from_another_user(message_dict: Dict[str, Any], current_u
     zulip/zulip project, so refactor with care.  See the comments in
     extract_query_without_mention.
     """
-    if message_dict['type'] == 'private':
-        return current_user_id != message_dict['sender_id']
-    return False
+    if not message_dict['type'] == 'private':
+        return False
+    is_message_from_self = current_user.user_id == message_dict['sender_id']
+    recipients = [x['email'] for x in message_dict['display_recipient'] if current_user.email != x['email']]
+    return len(recipients) == 1 and not is_message_from_self
 
 
 def display_config_file_errors(error_msg: str, config_file: str) -> None:
@@ -346,7 +348,7 @@ def run_message_handler_for_bot(
         # `mentioned` will be in `flags` if the bot is mentioned at ANY position
         # (not necessarily the first @mention in the message).
         is_mentioned = 'mentioned' in flags
-        is_private_message = is_private_message_from_another_user(message, restricted_client.user_id)
+        is_private_message = is_private_message_but_not_group_pm(message, restricted_client)
 
         # Provide bots with a way to access the full, unstripped message
         message['full_content'] = message['content']
diff --git a/zulip_bots/zulip_bots/tests/test_lib.py b/zulip_bots/zulip_bots/tests/test_lib.py
index 9d60ccf..c6116ae 100644
--- a/zulip_bots/zulip_bots/tests/test_lib.py
+++ b/zulip_bots/zulip_bots/tests/test_lib.py
@@ -4,7 +4,8 @@ from zulip_bots.lib import (
     ExternalBotHandler,
     StateHandler,
     run_message_handler_for_bot,
-    extract_query_without_mention
+    extract_query_without_mention,
+    is_private_message_but_not_group_pm
 )
 
 import io
@@ -209,6 +210,27 @@ class LibTest(TestCase):
         message = {'content': "Not at start @**Alice|alice** Hello World"}
         self.assertEqual(extract_query_without_mention(message, handler), None)
 
+    def test_is_private_message_but_not_group_pm(self):
+        client = FakeClient()
+        handler = ExternalBotHandler(
+            client=client,
+            root_dir=None,
+            bot_details=None,
+            bot_config_file=None
+        )
+        message = {}
+        message['display_recipient'] = 'some stream'
+        message['type'] = 'stream'
+        self.assertFalse(is_private_message_but_not_group_pm(message, handler))
+        message['type'] = 'private'
+        message['display_recipient'] = [{'email': 'a1@b.com'}]
+        message['sender_id'] = handler.user_id
+        self.assertFalse(is_private_message_but_not_group_pm(message, handler))
+        message['sender_id'] = 0  # someone else
+        self.assertTrue(is_private_message_but_not_group_pm(message, handler))
+        message['display_recipient'] = [{'email': 'a1@b.com'}, {'email': 'a2@b.com'}]
+        self.assertFalse(is_private_message_but_not_group_pm(message, handler))
+
     def _create_client_and_handler_for_file_upload(self):
         client = FakeClient()
         client.upload_file = MagicMock()