diff --git a/tests/requirements-py3.txt b/tests/requirements-py3.txt
index 8169febea..c4bc1f278 100644
--- a/tests/requirements-py3.txt
+++ b/tests/requirements-py3.txt
@@ -1,6 +1,7 @@
 # Tests requirements
 jmespath
-mitmproxy
+mitmproxy; python_version >= '3.6'
+mitmproxy==3.0.4; python_version < '3.6'
 pytest
 pytest-cov
 pytest-twisted