diff --git a/backend/open_webui/models/channels.py b/backend/open_webui/models/channels.py
index a78c3b05e0..5d452b0216 100644
--- a/backend/open_webui/models/channels.py
+++ b/backend/open_webui/models/channels.py
@@ -7,7 +7,7 @@ from open_webui.internal.db import Base, get_db
 from open_webui.utils.access_control import has_access
 
 from pydantic import BaseModel, ConfigDict
-from sqlalchemy import BigInteger, Boolean, Column, String, Text, JSON
+from sqlalchemy import BigInteger, Boolean, Column, String, Text, JSON, case
 from sqlalchemy import or_, func, select, and_, text
 from sqlalchemy.sql import exists
 
@@ -196,11 +196,23 @@ class ChannelTable:
 
     def get_dm_channel_by_user_ids(self, user_ids: list[str]) -> Optional[ChannelModel]:
         with get_db() as db:
+            # Ensure uniqueness in case a list with duplicates is passed
+            unique_user_ids = list(set(user_ids))
+
+            match_count = func.sum(
+                case(
+                    (ChannelMember.user_id.in_(unique_user_ids), 1),
+                    else_=0,
+                )
+            )
+
             subquery = (
                 db.query(ChannelMember.channel_id)
-                .filter(ChannelMember.user_id.in_(user_ids))
                 .group_by(ChannelMember.channel_id)
-                .having(func.count(ChannelMember.user_id) == len(user_ids))
+                # 1. Channel must have exactly len(user_ids) members
+                .having(func.count(ChannelMember.user_id) == len(unique_user_ids))
+                # 2. All those members must be in unique_user_ids
+                .having(match_count == len(unique_user_ids))
                 .subquery()
             )