diff --git a/requirements.txt b/requirements.txt
index 53c6398b..598f2e17 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,10 +4,10 @@
 # Everything needed to develop (test, debug) the framework.
 coverage<5.0  # manual enforcement where pip fails, see #272.
 pytest-aiohttp
-pytest-asyncio
-pytest-mock>=1.11.1
+pytest-asyncio==0.10.0  # until fixed: https://github.com/pytest-dev/pytest-asyncio/issues/154
+pytest-mock
 pytest-cov
-pytest
+pytest==5.3.5  # until fixed: https://github.com/pytest-dev/pytest-asyncio/issues/154
 aresponses
 asynctest
 freezegun
diff --git a/tests/conftest.py b/tests/conftest.py
index b149fa13..6471bcf7 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -42,15 +42,19 @@ def pytest_addoption(parser):
     parser.addoption("--with-e2e", action="store_true", help="Include end-to-end tests.")
 
 
+# Make all tests in this directory and below asyncio-compatible by default.
+# Due to how pytest-async checks for these markers, they should be added as early as possible.
+@pytest.hookimpl(hookwrapper=True)
+def pytest_pycollect_makeitem(collector, name, obj):
+    if collector.funcnamefilter(name) and asyncio.iscoroutinefunction(obj):
+        pytest.mark.asyncio(obj)
+    yield
+
+
 # This logic is not applied if pytest is started explicitly on ./examples/.
 # In that case, regular pytest behaviour applies -- this is intended.
 def pytest_collection_modifyitems(config, items):
 
-    # Make all tests in this directory and below asyncio-compatible by default.
-    for item in items:
-        if asyncio.iscoroutinefunction(item.function):
-            item.add_marker('asyncio')
-
     # Put all e2e tests to the end, as they are assumed to be slow.
     def _is_e2e(item):
         path = item.location[0]