diff --git a/tests/api/v1/endpoints/test_cyclonedx.py b/tests/api/v1/endpoints/test_cyclonedx.py
index 7d4d7b1..d40a88f 100644
--- a/tests/api/v1/endpoints/test_cyclonedx.py
+++ b/tests/api/v1/endpoints/test_cyclonedx.py
@@ -4,13 +4,13 @@
 from mihama import schemas
 
 
-@pytest.fixture()
+@pytest.fixture
 def bom():
     with open("tests/fixtures/cyclonedx/example.json") as f:
         return schemas.CycloneDX.model_validate_json(f.read())
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_cyclonedx(client: AsyncClient, bom: schemas.CycloneDX):
     res = await client.post("/v1/cyclonedx/querybatch", json=bom.model_dump())
diff --git a/tests/api/v1/endpoints/test_query.py b/tests/api/v1/endpoints/test_query.py
index e25e9a5..c17324d 100644
--- a/tests/api/v1/endpoints/test_query.py
+++ b/tests/api/v1/endpoints/test_query.py
@@ -4,7 +4,7 @@
 from mihama import schemas
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_query(client: AsyncClient, vulns: list[schemas.Vulnerability]):
     for v in vulns:
@@ -21,7 +21,7 @@ async def test_query(client: AsyncClient, vulns: list[schemas.Vulnerability]):
                 assert len(vulns) > 0
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_querybatch(client: AsyncClient, vulns: list[schemas.Vulnerability]):
     queries = []
diff --git a/tests/api/v1/endpoints/test_spdx.py b/tests/api/v1/endpoints/test_spdx.py
index 469a0cf..6a04581 100644
--- a/tests/api/v1/endpoints/test_spdx.py
+++ b/tests/api/v1/endpoints/test_spdx.py
@@ -4,13 +4,13 @@
 from mihama import schemas
 
 
-@pytest.fixture()
+@pytest.fixture
 def bom():
     with open("tests/fixtures/spdx/example.json") as f:
         return schemas.SPDX.model_validate_json(f.read())
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_spdx(client: AsyncClient, bom: schemas.SPDX):
     res = await client.post("/v1/spdx/querybatch", json=bom.model_dump())
diff --git a/tests/api/v1/endpoints/test_vulns.py b/tests/api/v1/endpoints/test_vulns.py
index 9538446..9f506bb 100644
--- a/tests/api/v1/endpoints/test_vulns.py
+++ b/tests/api/v1/endpoints/test_vulns.py
@@ -4,7 +4,7 @@
 from mihama import schemas
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_get_by_id(
     client: AsyncClient,
@@ -15,7 +15,7 @@ async def test_get_by_id(
         assert res.status_code == 200
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 async def test_search(client: AsyncClient, vulns: list[schemas.Vulnerability]):
     for v in vulns:
         for affected in v.affected:
diff --git a/tests/conftest.py b/tests/conftest.py
index 2aad12a..3553e99 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -64,7 +64,7 @@ async def get_es():
     await es.close()
 
 
-@pytest.fixture()
+@pytest.fixture
 async def es():
     async with get_es() as es:
         yield es
@@ -81,14 +81,14 @@ async def _setup_vulns(vulns: list[schemas.Vulnerability], docker_compose):
         await crud.vulnerability.bulk_index(es, vulns, refresh=True)
 
 
-@pytest.fixture()
+@pytest.fixture
 def app(_setup_vulns, es: AsyncElasticsearch, docker_compose):
     app = create_app(set_lifespan=False)
     app.dependency_overrides[deps.get_es] = lambda: es
     return app
 
 
-@pytest.fixture()
+@pytest.fixture
 async def client(app: FastAPI):
     async with httpx.AsyncClient(
         transport=httpx.ASGITransport(app=app),  # type: ignore
diff --git a/tests/crud/test_crud_index.py b/tests/crud/test_crud_index.py
index 6d345ff..387e39f 100644
--- a/tests/crud/test_crud_index.py
+++ b/tests/crud/test_crud_index.py
@@ -4,7 +4,7 @@
 from mihama import crud
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("docker_compose")
 async def test_exists(es: AsyncElasticsearch):
     got = await crud.index.exists(es, index="404_not_found")
diff --git a/tests/crud/test_crud_vulnerability.py b/tests/crud/test_crud_vulnerability.py
index d24e9dd..9d44464 100644
--- a/tests/crud/test_crud_vulnerability.py
+++ b/tests/crud/test_crud_vulnerability.py
@@ -4,14 +4,14 @@
 from mihama import crud, schemas
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_get(vulns: list[schemas.Vulnerability], es: AsyncElasticsearch):
     for v in vulns:
         assert await crud.vulnerability.get(es, v.id) is not None
 
 
-@pytest.fixture()
+@pytest.fixture
 def purls(vulns: list[schemas.Vulnerability]):
     purls: set[str] = set()
     for v in vulns:
@@ -22,7 +22,7 @@ def purls(vulns: list[schemas.Vulnerability]):
     return purls
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_search_by_package_purl(purls: set[str], es: AsyncElasticsearch):
     for purl in purls:
@@ -32,7 +32,7 @@ async def test_search_by_package_purl(purls: set[str], es: AsyncElasticsearch):
         assert len(vulnerabilities) > 0
 
 
-@pytest.fixture()
+@pytest.fixture
 def package_names(vulns: list[schemas.Vulnerability]):
     names: set[str] = set()
     for v in vulns:
@@ -43,7 +43,7 @@ def package_names(vulns: list[schemas.Vulnerability]):
     return names
 
 
-@pytest.mark.asyncio()
+@pytest.mark.asyncio
 @pytest.mark.usefixtures("_setup_vulns")
 async def test_search_by_package_name(package_names: set[str], es: AsyncElasticsearch):
     for name in package_names:
diff --git a/tests/schemas/osv/test_fixed.py b/tests/schemas/osv/test_fixed.py
index c01fb6d..2197557 100644
--- a/tests/schemas/osv/test_fixed.py
+++ b/tests/schemas/osv/test_fixed.py
@@ -3,7 +3,7 @@
 from mihama import schemas
 
 
-@pytest.fixture()
+@pytest.fixture
 def vuln():
     # introduced: 0
     # fixed: 0.0.9
diff --git a/tests/schemas/osv/test_last_affected.py b/tests/schemas/osv/test_last_affected.py
index ec75e67..44306d6 100644
--- a/tests/schemas/osv/test_last_affected.py
+++ b/tests/schemas/osv/test_last_affected.py
@@ -3,7 +3,7 @@
 from mihama import schemas
 
 
-@pytest.fixture()
+@pytest.fixture
 def vuln():
     # introduced: 0
     # last_affected: 4.1.0
diff --git a/tests/schemas/osv/test_multi_packages_fixed.py b/tests/schemas/osv/test_multi_packages_fixed.py
index 6721a3c..de93287 100644
--- a/tests/schemas/osv/test_multi_packages_fixed.py
+++ b/tests/schemas/osv/test_multi_packages_fixed.py
@@ -3,14 +3,14 @@
 from mihama import schemas
 
 
-@pytest.fixture()
+@pytest.fixture
 def vuln():
     # the vulnerability has multiple packages in affected
     with open("tests/fixtures/advisories/multi_packages_fixed.json") as f:
         return schemas.Vulnerability.model_validate_json(f.read())
 
 
-@pytest.fixture()
+@pytest.fixture
 def plone_package():
     return schemas.Package(ecosystem="PyPI", name="Plone")
 
diff --git a/tests/schemas/osv/test_versions.py b/tests/schemas/osv/test_versions.py
index fd19019..f8c9ce6 100644
--- a/tests/schemas/osv/test_versions.py
+++ b/tests/schemas/osv/test_versions.py
@@ -3,7 +3,7 @@
 from mihama import schemas
 
 
-@pytest.fixture()
+@pytest.fixture
 def vuln():
     # versions: 3.2 to 5.2rc5
     with open("tests/fixtures/advisories/versions.json") as f:
diff --git a/tests/schemas/test_cyclonedx.py b/tests/schemas/test_cyclonedx.py
index c2800ce..d32aa66 100644
--- a/tests/schemas/test_cyclonedx.py
+++ b/tests/schemas/test_cyclonedx.py
@@ -4,7 +4,7 @@
 from mihama.schemas.cyclonedx import Component
 
 
-@pytest.fixture()
+@pytest.fixture
 def nested_component():
     # NOTE: it has 5 components in total (4 have purl, 1 does not have purl)
     with open("tests/fixtures/cyclonedx/nested_components.json") as f:
@@ -16,7 +16,7 @@ def test_get_flatten_components(nested_component: Component):
     assert len(flatten) == 5
 
 
-@pytest.fixture()
+@pytest.fixture
 def bom(nested_component: Component):
     return schemas.CycloneDX(components=[nested_component])
 
diff --git a/tests/schemas/test_spdx.py b/tests/schemas/test_spdx.py
index 1fd61e8..cb6e603 100644
--- a/tests/schemas/test_spdx.py
+++ b/tests/schemas/test_spdx.py
@@ -3,7 +3,7 @@
 from mihama import schemas
 
 
-@pytest.fixture()
+@pytest.fixture
 def spdx():
     # this file contains one PURL package only
     with open("tests/fixtures/spdx/example.json") as f:
diff --git a/tests/test_query.py b/tests/test_query.py
index b309f74..2c4def0 100644
--- a/tests/test_query.py
+++ b/tests/test_query.py
@@ -4,7 +4,7 @@
 from mihama.query import normalize_query
 
 
-@pytest.fixture()
+@pytest.fixture
 def query_with_package_with_purl_without_version():
     return schemas.Query(
         version=None, package=schemas.QueryPackage(purl="pkg:npm/jsrsasign")
@@ -18,7 +18,7 @@ def test_normalize_query_with_purl_without_version(
     assert normalized.version is None
 
 
-@pytest.fixture()
+@pytest.fixture
 def query_with_package_with_purl_with_version():
     return schemas.Query(
         version=None, package=schemas.QueryPackage(purl="pkg:npm/jsrsasign@0.1.0")