diff --git a/app/api/auth.py b/app/api/auth.py
index f13e3c3..74c3921 100644
--- a/app/api/auth.py
+++ b/app/api/auth.py
@@ -1,4 +1,4 @@
-import datetime
+import datetime as dt
 import typing
 
 import litestar
@@ -24,7 +24,7 @@ async def retrieve_user_handler(token: Token, _connection: ASGIConnection) -> Ac
 jwt_cookie_auth: typing.Final = JWTCookieAuth[Actor](
     retrieve_user_handler=retrieve_user_handler,
     token_secret=settings.jwt_secret,
-    default_token_expiration=datetime.timedelta(seconds=settings.jwt_lifetime_seconds),
+    default_token_expiration=dt.timedelta(seconds=settings.jwt_lifetime_seconds),
     secure=settings.jwt_cookie_secure,
     # Anchored: Litestar matches the joined patterns with an unanchored findall.
     exclude=[
diff --git a/app/database/tables.py b/app/database/tables.py
index 315dedb..be7df5e 100644
--- a/app/database/tables.py
+++ b/app/database/tables.py
@@ -1,4 +1,4 @@
-import datetime
+import datetime as dt
 import enum
 import typing
 import uuid
@@ -73,8 +73,8 @@ class ChatMembersTable(BigIntBase):
     chat_id: orm.Mapped[int] = orm.mapped_column(sa.ForeignKey("chats.id"))
     user_id: orm.Mapped[int] = orm.mapped_column(sa.ForeignKey("users.id"), index=True)
     last_read_message_id: orm.Mapped[int | None] = orm.mapped_column(sa.BigInteger, nullable=True)
-    joined_at: orm.Mapped[datetime.datetime] = orm.mapped_column(
-        DateTimeUTC(timezone=True), default=lambda: datetime.datetime.now(tz=datetime.UTC)
+    joined_at: orm.Mapped[dt.datetime] = orm.mapped_column(
+        DateTimeUTC(timezone=True), default=lambda: dt.datetime.now(tz=dt.UTC)
     )
 
 
@@ -89,8 +89,8 @@ class MessagesTable(BigIntBase):
     user_id: orm.Mapped[int | None] = orm.mapped_column(sa.ForeignKey("users.id"), nullable=True, index=True)
     idempotency_key: orm.Mapped[uuid.UUID] = orm.mapped_column(GUID)
     text: orm.Mapped[str] = orm.mapped_column(sa.String)
-    created_at: orm.Mapped[datetime.datetime] = orm.mapped_column(
-        DateTimeUTC(timezone=True), default=lambda: datetime.datetime.now(tz=datetime.UTC)
+    created_at: orm.Mapped[dt.datetime] = orm.mapped_column(
+        DateTimeUTC(timezone=True), default=lambda: dt.datetime.now(tz=dt.UTC)
     )
-    edited_at: orm.Mapped[datetime.datetime | None] = orm.mapped_column(DateTimeUTC(timezone=True), nullable=True)
-    deleted_at: orm.Mapped[datetime.datetime | None] = orm.mapped_column(DateTimeUTC(timezone=True), nullable=True)
+    edited_at: orm.Mapped[dt.datetime | None] = orm.mapped_column(DateTimeUTC(timezone=True), nullable=True)
+    deleted_at: orm.Mapped[dt.datetime | None] = orm.mapped_column(DateTimeUTC(timezone=True), nullable=True)
diff --git a/app/schemas/api.py b/app/schemas/api.py
index b87ddef..f0667eb 100644
--- a/app/schemas/api.py
+++ b/app/schemas/api.py
@@ -1,4 +1,4 @@
-import datetime
+import datetime as dt
 import uuid
 from collections.abc import Iterable
 from typing import Annotated, Any, Self
@@ -81,8 +81,8 @@ class Message(Base):
     chat_id: PositiveInt
     user_id: PositiveInt | None = None
     text: str
-    created_at: datetime.datetime
-    edited_at: datetime.datetime | None = None
+    created_at: dt.datetime
+    edited_at: dt.datetime | None = None
 
 
 class Messages(Collection[Message]):
diff --git a/app/use_cases/delete_message.py b/app/use_cases/delete_message.py
index 782de58..e0a1779 100644
--- a/app/use_cases/delete_message.py
+++ b/app/use_cases/delete_message.py
@@ -1,5 +1,5 @@
 import dataclasses
-import datetime
+import datetime as dt
 
 from db_retry import Transaction, postgres_retry
 
@@ -31,7 +31,7 @@ async def __call__(self, *, actor: Actor, message_id: int) -> None:
             if message.deleted_at is not None:
                 # DELETE is idempotent; a second delete is not an error, unlike an edit.
                 return
-            message.deleted_at = datetime.datetime.now(tz=datetime.UTC)
+            message.deleted_at = dt.datetime.now(tz=dt.UTC)
             await self.messages_repository.update(message, item_id=message_id)
 
             chat = await self.chats_repository.get_one(id=message.chat_id)
diff --git a/app/use_cases/edit_message.py b/app/use_cases/edit_message.py
index b4ff357..0b99773 100644
--- a/app/use_cases/edit_message.py
+++ b/app/use_cases/edit_message.py
@@ -1,5 +1,5 @@
 import dataclasses
-import datetime
+import datetime as dt
 
 from db_retry import Transaction, postgres_retry
 
@@ -32,7 +32,7 @@ async def __call__(self, *, actor: Actor, message_id: int, data: EditMessageRequ
                 msg = "This message has been deleted"
                 raise ConflictError(msg)
             message.text = data.text
-            message.edited_at = datetime.datetime.now(tz=datetime.UTC)
+            message.edited_at = dt.datetime.now(tz=dt.UTC)
             updated = await self.messages_repository.update(message, item_id=message_id)
             await self.transaction.commit()
             # Safe inside the block: commit() ended the transaction, so __aexit__ only closes.
diff --git a/tests/api/test_auth_api.py b/tests/api/test_auth_api.py
index 51b86d2..f605ada 100644
--- a/tests/api/test_auth_api.py
+++ b/tests/api/test_auth_api.py
@@ -1,4 +1,4 @@
-import datetime
+import datetime as dt
 
 import pytest
 import sqlalchemy as sa
@@ -141,5 +141,5 @@ async def test_retrieve_user_handler_resolves_an_actor_without_reading_the_datab
     foreign key. Nothing can reach that state today; a delete-user path would have to solve it
     alongside logout not revoking the JWT.
     """
-    token = Token(sub="42", exp=datetime.datetime.now(tz=datetime.UTC) + datetime.timedelta(minutes=5))
+    token = Token(sub="42", exp=dt.datetime.now(tz=dt.UTC) + dt.timedelta(minutes=5))
     assert await retrieve_user_handler(token, None) == Actor(id=42)  # ty: ignore[invalid-argument-type]