diff --git a/yunke-server/app/api/routers/customer.py b/yunke-server/app/api/routers/customer.py
index 6d42e55..a65a0cc 100644
--- a/yunke-server/app/api/routers/customer.py
+++ b/yunke-server/app/api/routers/customer.py
@@ -71,7 +71,6 @@ async def list_customers(
         list_stmt = list_stmt.where(*conditions)
     list_stmt = (
         list_stmt.order_by(
-            sa.nullslast(Customer.last_chat_time.desc()),
             Customer.friend_id.asc(),
         )
         .limit(page_size)
diff --git a/yunke-server/app/api/routers/groups.py b/yunke-server/app/api/routers/groups.py
index b5c2e69..8717bcc 100644
--- a/yunke-server/app/api/routers/groups.py
+++ b/yunke-server/app/api/routers/groups.py
@@ -61,7 +61,6 @@ async def list_groups(
         list_stmt = list_stmt.where(*conditions)
     list_stmt = (
         list_stmt.order_by(
-            sa.nullslast(ChatGroup.last_chat_time.desc()),
             ChatGroup.room_id.asc(),
         )
         .limit(page_size)
diff --git a/yunke-server/tests/test_api_customer.py b/yunke-server/tests/test_api_customer.py
index 32308ea..6cffc0f 100644
--- a/yunke-server/tests/test_api_customer.py
+++ b/yunke-server/tests/test_api_customer.py
@@ -205,19 +205,17 @@ async def test_pagination_page_size_one(client: AsyncClient):
     assert len(body["items"]) == 1
 
 
-async def test_order_is_last_chat_time_desc_nulls_last(client: AsyncClient):
-    """Order: ``last_chat_time desc`` (nulls last), then ``friend_id``.
+async def test_order_is_friend_id_asc(client: AsyncClient):
+    """Order: ``friend_id ASC`` (natural API/云客 order).
 
-    Seeded rows have last_chat_time 2000 / 1000 / None -> expected order
-    ``[wx_a, wx_b, wa_c]`` (the whatsapp row with NULL last_chat_time lands
-    last even though it has no timestamp).
+    Seeded IDs wa_c < wx_a < wx_b → expected order ``[wa_c, wx_a, wx_b]``.
     """
     r = await client.get(
         "/api/customers", params={"page": 1, "page_size": 20}
     )
     assert r.status_code == 200
     ids = [it["friend_id"] for it in r.json()["items"]]
-    assert ids == ["wx_a", "wx_b", "wa_c"]
+    assert ids == ["wa_c", "wx_a", "wx_b"]
 
 
 async def test_filter_by_owner_account_id(client: AsyncClient):