diff --git a/tests/requirements-py3.txt b/tests/requirements-py3.txt
index 4fa58d11b..b67c08403 100644
--- a/tests/requirements-py3.txt
+++ b/tests/requirements-py3.txt
@@ -1,7 +1,8 @@
 # Tests requirements
 attrs
 dataclasses; python_version == '3.6'
-mitmproxy >=4, <5  # The latest version does not support some pinned dependencies
+mitmproxy >=4, <5; python_version < '3.6'  # The latest version does not support some pinned dependencies
+mitmproxy <4; python_version < '3.6'
 # https://github.com/pytest-dev/pytest-twisted/issues/93
 pytest != 5.4, != 5.4.1
 pytest-azurepipelines