diff --git a/docs/api-reference.md b/docs/api-reference.md
index f5bb297..c1a0095 100644
--- a/docs/api-reference.md
+++ b/docs/api-reference.md
@@ -978,6 +978,10 @@ Body:
 
 Response: `200` + `MessageRead`
 
+Errors:
+
+- `403` - not message author or message is older than 7 days.
+
 ### DELETE `/api/v1/messages/{message_id}?for_all=false`
 
 Auth required.  
diff --git a/docs/core-checklist-status.md b/docs/core-checklist-status.md
index 6a14cc0..f2d517f 100644
--- a/docs/core-checklist-status.md
+++ b/docs/core-checklist-status.md
@@ -14,7 +14,7 @@ Legend:
 5. Chat List - `DONE` (all/pinned/archive/sort/unread)
 6. Chat Types - `DONE` (private/group/channel)
 7. Chat Creation - `DONE` (private/group/channel)
-8. Messages (base) - `DONE` (send/read/edit/delete/delete for all; group UI shows sender names over bubbles + sender avatars on incoming message clusters)
+8. Messages (base) - `DONE` (send/read/edit/delete/delete for all; 7-day edit window enforced and covered by integration tests; group UI shows sender names over bubbles + sender avatars on incoming message clusters)
 9. Message Types - `PARTIAL` (text/photo/video/docs/audio/voice/circle; GIF/stickers via dedicated system missing)
 10. Reply/Quote/Threads - `PARTIAL` (reply + quote-like UI + thread panel with nested replies, no dedicated full thread navigation yet)
 11. Forwarding - `DONE` (single + bulk + without author)
diff --git a/tests/test_chat_message_flow.py b/tests/test_chat_message_flow.py
index b860845..625944d 100644
--- a/tests/test_chat_message_flow.py
+++ b/tests/test_chat_message_flow.py
@@ -1,7 +1,10 @@
+from datetime import datetime, timedelta, timezone
+
 from sqlalchemy import select
 
 from app.auth.models import EmailVerificationToken
 from app.chats.models import ChatType
+from app.messages.models import Message
 
 
 async def _create_verified_user(client, db_session, email: str, username: str, password: str) -> dict:
@@ -61,6 +64,43 @@ async def test_private_chat_message_lifecycle(client, db_session):
     assert delete_message_response.status_code == 204
 
 
+async def test_edit_message_older_than_7_days_is_forbidden(client, db_session):
+    u1 = await _create_verified_user(client, db_session, "edit_older_u1@example.com", "edit_older_u1", "strongpass123")
+    u2 = await _create_verified_user(client, db_session, "edit_older_u2@example.com", "edit_older_u2", "strongpass123")
+
+    me_u2 = await client.get("/api/v1/auth/me", headers={"Authorization": f"Bearer {u2['access_token']}"})
+    u2_id = me_u2.json()["id"]
+
+    create_chat_response = await client.post(
+        "/api/v1/chats",
+        headers={"Authorization": f"Bearer {u1['access_token']}"},
+        json={"type": ChatType.PRIVATE.value, "title": None, "member_ids": [u2_id]},
+    )
+    assert create_chat_response.status_code == 200
+    chat_id = create_chat_response.json()["id"]
+
+    send_message_response = await client.post(
+        "/api/v1/messages",
+        headers={"Authorization": f"Bearer {u1['access_token']}"},
+        json={"chat_id": chat_id, "type": "text", "text": "original"},
+    )
+    assert send_message_response.status_code == 201
+    message_id = send_message_response.json()["id"]
+
+    message_row = await db_session.execute(select(Message).where(Message.id == message_id))
+    message = message_row.scalar_one()
+    message.created_at = datetime.now(timezone.utc) - timedelta(days=8)
+    await db_session.commit()
+
+    edit_message_response = await client.put(
+        f"/api/v1/messages/{message_id}",
+        headers={"Authorization": f"Bearer {u1['access_token']}"},
+        json={"text": "edited text"},
+    )
+    assert edit_message_response.status_code == 403
+    assert "7 days" in edit_message_response.json().get("detail", "")
+
+
 async def test_private_chat_respects_contacts_only_policy(client, db_session):
     u1 = await _create_verified_user(client, db_session, "pm_u1@example.com", "pm_user_one", "strongpass123")
     u2 = await _create_verified_user(client, db_session, "pm_u2@example.com", "pm_user_two", "strongpass123")