diff --git a/api/tests/conftest.py b/api/tests/conftest.py
index dedfcae2b2..d5f5781f4f 100644
--- a/api/tests/conftest.py
+++ b/api/tests/conftest.py
@@ -1,6 +1,6 @@
 import pytest_asyncio
 import requests
-from httpx import AsyncClient
+from httpx import ASGITransport, AsyncClient
 
 from app.main import app
 
@@ -27,7 +27,7 @@ def mock_txt_file(tmpdir_factory):
 @pytest_asyncio.fixture(scope="function")
 async def test_app_asyncio():
     # for httpx>=20, follow_redirects=True (cf. https://github.com/encode/httpx/releases/tag/0.20.0)
-    async with AsyncClient(app=app, base_url="http://test", follow_redirects=True) as ac:
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test", follow_redirects=True) as ac:
         yield ac  # testing happens here