diff --git a/tox.ini b/tox.ini
index b69e5e7..8a9f653 100644
--- a/tox.ini
+++ b/tox.ini
@@ -18,6 +18,7 @@ envlist =
 deps =
     setuptools  <74
     py37: urllib3 < 2
+    git+https://github.com/zopefoundation/zope.security@9bba9b94e3fd55c6916e97881bd633b9cb15644c#egg=zope.security
 setenv =
     pure: PURE_PYTHON=1
     !pure-!pypy3: PURE_PYTHON=0