diff --git a/conftest.py b/conftest.py
--- a/conftest.py
+++ b/conftest.py
@@ -18,3 +18,8 @@
     yield _swhmain
     _swhmain.commands = commands
     _swhmain.aliases = aliases
+
+
+# This is coming from the aiohttp library directly. Beware the desynchronized
+# https://github.com/aio-libs/pytest-aiohttp module which wraps that library...
+pytest_plugins = ["aiohttp.pytest_plugin"]
diff --git a/swh/core/api/tests/conftest.py b/swh/core/api/tests/conftest.py
--- a/swh/core/api/tests/conftest.py
+++ b/swh/core/api/tests/conftest.py
@@ -1,3 +0,0 @@
-# This is coming from the aiohttp library directly. Beware the desynchronized
-# https://github.com/aio-libs/pytest-aiohttp module which wraps that library...
-pytest_plugins = ["aiohttp.pytest_plugin"]