diff --git a/requirements-dev.txt b/requirements-dev.txt
index 6edee41781..e29f2474d2 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -6,6 +6,7 @@ pytest-mock==2.0.0
 httpbin==0.7.0
 trustme
 wheel
+cryptography<40.0.0; python_version <= '3.7' and platform_python_implementation == 'PyPy'
 
 # Flask Stack
 Flask>1.0,<2.0