diff --git a/src/outcome/_async.py b/src/outcome/_async.py
index a9ec1ba..4fd64af 100644
--- a/src/outcome/_async.py
+++ b/src/outcome/_async.py
@@ -48,13 +48,13 @@ class Outcome(OutcomeBase):
         """
 
 
-class Value(ValueBase):
+class Value(Outcome, ValueBase):
     async def asend(self, agen):
         self._set_unwrapped()
         return await agen.asend(self.value)
 
 
-class Error(ErrorBase):
+class Error(Outcome, ErrorBase):
     async def asend(self, agen):
         self._set_unwrapped()
         return await agen.athrow(self.error)

Unintuitive inheritance in Python 3.5+
```python
v = outcome.Value(100)
isinstance(v, outcome.Outcome)
# False
e = outcome.Error(Exception('Boom!'))
isinstance(e, outcome.Outcome)
# False
```
I would expect both inherit from `outcome.Outcome`.
diff --git a/tests/test_sync.py b/tests/test_sync.py
index 192ac21..10d1ee8 100644
--- a/tests/test_sync.py
+++ b/tests/test_sync.py
@@ -103,3 +103,8 @@ def test_capture():
     assert type(e) == Error
     assert type(e.error) is ValueError
     assert e.error.args == ("two",)
+
+
+def test_inheritance():
+    assert issubclass(Value, outcome.Outcome)
+    assert issubclass(Error, outcome.Outcome)

pip install -e .
parse_log_pytest
pytest
pytest
3.6.4
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs @ file:///opt/conda/conda-bld/attrs_1642510447205/work
certifi==2021.5.30
importlib-metadata @ file:///tmp/build/80754af9/importlib-metadata_1631916693255/work
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
more-itertools @ file:///tmp/build/80754af9/more-itertools_1637733554872/work
-e git+https://github.com/python-trio/outcome.git@4ec1933665061a13aec147f0baeff3d180b2cb27#egg=outcome
packaging @ file:///tmp/build/80754af9/packaging_1637314298585/work
pluggy @ file:///tmp/build/80754af9/pluggy_1615976315926/work
py @ file:///opt/conda/conda-bld/py_1644396412707/work
pyparsing @ file:///tmp/build/80754af9/pyparsing_1635766073266/work
pytest==6.2.4
toml @ file:///tmp/build/80754af9/toml_1616166611790/work
typing_extensions @ file:///opt/conda/conda-bld/typing_extensions_1647553014482/work
zipp @ file:///tmp/build/80754af9/zipp_1633618647012/work

name: outcome
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
  - attrs=21.4.0=pyhd3eb1b0_0
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - importlib-metadata=4.8.1=py36h06a4308_0
  - importlib_metadata=4.8.1=hd3eb1b0_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - libedit=3.1.20230828=h5eee18b_0
  - libffi=3.2.1=hf484d3e_1007
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - more-itertools=8.12.0=pyhd3eb1b0_0
  - ncurses=6.4=h6a678d5_0
  - openssl=1.0.2u=h7b6447c_0
  - packaging=21.3=pyhd3eb1b0_0
  - pip=21.2.2=py36h06a4308_0
  - pluggy=0.13.1=py36h06a4308_0
  - py=1.11.0=pyhd3eb1b0_0
  - pyparsing=3.0.4=pyhd3eb1b0_0
  - pytest=6.2.4=py36h06a4308_2
  - python=3.6.4=hc3d631a_3
  - readline=7.0=h7b6447c_5
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.33.0=h62c20be_0
  - tk=8.6.14=h39e8969_0
  - toml=0.10.2=pyhd3eb1b0_0
  - typing_extensions=4.1.1=pyh06a4308_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zipp=3.6.0=pyhd3eb1b0_0
  - zlib=1.2.13=h5eee18b_1
prefix: /opt/conda/envs/outcome

tests/test_sync.py::test_inheritance
tests/test_sync.py::test_Outcome tests/test_sync.py::test_Outcome_eq_hash tests/test_sync.py::test_Value_compare tests/test_sync.py::test_capture
src/outcome/_async.py
src/outcome/_async.py