diff --git a/llm/default_plugins/openai_models.py b/llm/default_plugins/openai_models.py
index ab33d1b..3d41858 100644
--- a/llm/default_plugins/openai_models.py
+++ b/llm/default_plugins/openai_models.py
@@ -182,8 +182,8 @@ def register_commands(cli):
             to_print = []
             for model in models:
                 # Print id, owned_by, root, created as ISO 8601
-                created_str = datetime.datetime.utcfromtimestamp(
-                    model["created"]
+                created_str = datetime.datetime.fromtimestamp(
+                    model["created"], datetime.timezone.utc
                 ).isoformat()
                 to_print.append(
                     {
diff --git a/llm/migrations.py b/llm/migrations.py
index b8ac8b1..3575b9e 100644
--- a/llm/migrations.py
+++ b/llm/migrations.py
@@ -13,7 +13,10 @@ def migrate(db):
         if name not in already_applied:
             fn(db)
             db["_llm_migrations"].insert(
-                {"name": name, "applied_at": str(datetime.datetime.utcnow())}
+                {
+                    "name": name,
+                    "applied_at": str(datetime.datetime.now(datetime.timezone.utc)),
+                }
             )
             already_applied.add(name)
 
diff --git a/llm/models.py b/llm/models.py
index 8f7849e..8a75dc4 100644
--- a/llm/models.py
+++ b/llm/models.py
@@ -385,7 +385,7 @@ class Response(_BaseResponse):
 
     def __iter__(self) -> Iterator[str]:
         self._start = time.monotonic()
-        self._start_utcnow = datetime.datetime.utcnow()
+        self._start_utcnow = datetime.datetime.now(datetime.timezone.utc)
         if self._done:
             yield from self._chunks
             return
@@ -434,7 +434,7 @@ class AsyncResponse(_BaseResponse):
 
     def __aiter__(self):
         self._start = time.monotonic()
-        self._start_utcnow = datetime.datetime.utcnow()
+        self._start_utcnow = datetime.datetime.now(datetime.timezone.utc)
         return self
 
     async def __anext__(self) -> str:
diff --git a/tests/test_cli_openai_models.py b/tests/test_cli_openai_models.py
index 3d0a7c1..fbb382d 100644
--- a/tests/test_cli_openai_models.py
+++ b/tests/test_cli_openai_models.py
@@ -35,9 +35,9 @@ def test_openai_models(mocked_models):
     result = runner.invoke(cli, ["openai", "models", "--key", "x"])
     assert result.exit_code == 0
     assert result.output == (
-        "id                    owned_by    created            \n"
-        "ada:2020-05-03        openai      2020-05-03T20:26:40\n"
-        "babbage:2020-05-03    openai      2020-05-03T20:26:40\n"
+        "id                    owned_by    created                  \n"
+        "ada:2020-05-03        openai      2020-05-03T20:26:40+00:00\n"
+        "babbage:2020-05-03    openai      2020-05-03T20:26:40+00:00\n"
     )
 
 
diff --git a/tests/test_llm.py b/tests/test_llm.py
index f23bf71..79aa147 100644
--- a/tests/test_llm.py
+++ b/tests/test_llm.py
@@ -28,7 +28,7 @@ def log_path(user_path):
     log_path = str(user_path / "logs.db")
     db = sqlite_utils.Database(log_path)
     migrate(db)
-    start = datetime.datetime.utcnow()
+    start = datetime.datetime.now(datetime.timezone.utc)
     db["responses"].insert_all(
         {
             "id": str(ULID()).lower(),