diff --git a/HISTORY.rst b/HISTORY.rst
index 485c825..f5a2f8c 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -1,6 +1,12 @@
 History
 =======
 
+* Correctly return naive datetimes from ``datetime.utcnow()`` whilst time
+  travelling.
+
+  Thanks to Søren Pilgård and Bart Van Loon for the report in
+  `Issue #52 <https://github.com/adamchainz/time-machine/issues/52>`__.
+
 1.2.0 (2020-07-08)
 ------------------
 
diff --git a/src/time_machine.py b/src/time_machine.py
index 0832f6a..d0ed6ff 100644
--- a/src/time_machine.py
+++ b/src/time_machine.py
@@ -206,7 +206,7 @@ def utcnow():
     if not coordinates_stack:
         return _time_machine.original_utcnow()
     else:
-        return dt.datetime.fromtimestamp(time(), dt.timezone.utc)
+        return dt.datetime.utcfromtimestamp(time())
 
 
 # time module

datetime.datetime.utcnow() should not have tzinfo
Hi, I find this library very neat and have started using it in multiple tests.
But there is one issue:

```python
In [1]: import datetime

In [2]: import time_machine

In [3]: @time_machine.travel("2020-07-28 13:15:30.478705")
   ...: def foo():
   ...:     return datetime.datetime.utcnow()
   ...:

In [4]: datetime.datetime.utcnow()
Out[4]: datetime.datetime(2020, 7, 31, 13, 46, 25, 828701)

In [5]: foo()
Out[5]: datetime.datetime(2020, 7, 28, 13, 15, 30, 478705, tzinfo=datetime.timezone.utc)
```

time_machine adds a timezone on datetime instances created via `.utcnow()` but this is wrong according to python.
It even specifies it directly in the documentation https://docs.python.org/3/library/datetime.html#datetime.datetime.utcnow
> Return the current UTC date and time, **with tzinfo None**.

This change in the behaviour of the datetime library can cause changes in behaviour of the tested code.
Eg. when serialized to a string it adds "+00:00"


diff --git a/tests/test_time_machine.py b/tests/test_time_machine.py
index bf85da5..4eacde2 100644
--- a/tests/test_time_machine.py
+++ b/tests/test_time_machine.py
@@ -88,6 +88,7 @@ def test_datetime_utcnow():
         assert now.minute == 0
         assert now.second == 0
         assert now.microsecond == 0
+        assert now.tzinfo is None
     assert dt.datetime.utcnow() >= LIBRARY_EPOCH_DATETIME
 
 

pip install -e .
parse_log_pytest
requirements.txt
pytest
apt-get update apt-get install -y gcc
3.8
requirements/py38.txt
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
appdirs==1.4.4
exceptiongroup==1.2.2
iniconfig==2.1.0
packaging==24.2
pluggy==1.5.0
pytest==8.3.5
python-dateutil==2.9.0.post0
six==1.17.0
-e git+https://github.com/adamchainz/time-machine.git@48a2a4df24ba188533fdf03f6cfc4b78db33f17a#egg=time_machine
tomli==2.2.1

name: time-machine
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - ca-certificates=2025.2.25=h06a4308_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.4.4=h6a678d5_1
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - ncurses=6.4=h6a678d5_0
  - openssl=3.0.16=h5eee18b_0
  - pip=24.2=py38h06a4308_0
  - python=3.8.20=he870216_0
  - readline=8.2=h5eee18b_0
  - setuptools=75.1.0=py38h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - wheel=0.44.0=py38h06a4308_0
  - xz=5.6.4=h5eee18b_1
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - appdirs==1.4.4
      - exceptiongroup==1.2.2
      - iniconfig==2.1.0
      - packaging==24.2
      - pluggy==1.5.0
      - pytest==8.3.5
      - python-dateutil==2.9.0.post0
      - six==1.17.0
      - time-machine==1.2.0
      - tomli==2.2.1
prefix: /opt/conda/envs/time-machine

tests/test_time_machine.py::test_datetime_utcnow
tests/test_time_machine.py::test_import_without_clock_realtime tests/test_time_machine.py::test_datetime_now_no_args tests/test_time_machine.py::test_datetime_now_no_args_no_tick tests/test_time_machine.py::test_datetime_now_arg tests/test_time_machine.py::test_datetime_utcnow_no_tick tests/test_time_machine.py::test_date_today tests/test_time_machine.py::test_time_clock_gettime_realtime tests/test_time_machine.py::test_time_clock_gettime_monotonic_unaffected tests/test_time_machine.py::test_time_clock_gettime_ns_realtime tests/test_time_machine.py::test_time_clock_gettime_ns_monotonic_unaffected tests/test_time_machine.py::test_time_gmtime_no_args tests/test_time_machine.py::test_time_gmtime_no_args_no_tick tests/test_time_machine.py::test_time_gmtime_arg tests/test_time_machine.py::test_time_localtime tests/test_time_machine.py::test_time_localtime_no_tick tests/test_time_machine.py::test_time_localtime_arg tests/test_time_machine.py::test_time_strftime_no_args tests/test_time_machine.py::test_time_strftime_no_args_no_tick tests/test_time_machine.py::test_time_strftime_arg tests/test_time_machine.py::test_time_time tests/test_time_machine.py::test_time_time_no_tick tests/test_time_machine.py::test_time_time_ns tests/test_time_machine.py::test_time_time_ns_no_tick tests/test_time_machine.py::test_nestable tests/test_time_machine.py::test_unsupported_type tests/test_time_machine.py::test_exceptions_dont_break_it tests/test_time_machine.py::test_destination_datetime tests/test_time_machine.py::test_destination_datetime_timezone tests/test_time_machine.py::test_destination_datetime_naive tests/test_time_machine.py::test_destination_date tests/test_time_machine.py::test_destination_string tests/test_time_machine.py::test_destination_callable_lambda_float tests/test_time_machine.py::test_destination_callable_lambda_string tests/test_time_machine.py::test_destination_generator tests/test_time_machine.py::test_traveller_object tests/test_time_machine.py::test_function_decorator tests/test_time_machine.py::test_coroutine_decorator tests/test_time_machine.py::test_class_decorator_fails_non_testcase tests/test_time_machine.py::UnitTestMethodTests::test_method_decorator tests/test_time_machine.py::UnitTestClassTests::test_class_decorator tests/test_time_machine.py::UnitTestClassTests::test_stacked_method_decorator tests/test_time_machine.py::UnitTestClassCustomSetUpClassTests::test_class_decorator tests/test_time_machine.py::test_tz_offset_float tests/test_time_machine.py::test_tz_offset_timedelta tests/test_time_machine.py::test_tz_offset_unsupported_type tests/test_time_machine.py::test_shift_with_timedelta tests/test_time_machine.py::test_shift_integer_delta tests/test_time_machine.py::test_shift_negative_delta tests/test_time_machine.py::test_shift_wrong_delta tests/test_time_machine.py::test_shift_when_tick tests/test_time_machine.py::test_move_to_datetime tests/test_time_machine.py::test_move_to_datetime_when_tick tests/test_time_machine.py::test_move_to_past_datetime tests/test_time_machine.py::test_move_to_past_datetime_when_tick tests/test_time_machine.py::test_uuid1
HISTORY.rst src/time_machine.py
HISTORY.rst src/time_machine.py