diff --git a/test-plone-4.3.7.cfg b/test-plone-4.3.7.cfg
index 1146c15..dc51ef7 100644
--- a/test-plone-4.3.7.cfg
+++ b/test-plone-4.3.7.cfg
@@ -19,3 +19,4 @@ Products.DateRecurringIndex = 2.1
 collective.elephantvocabulary = 0.2.5
 plone.formwidget.querystring = 1.1.10
 plone.event = 1.3.3
+certifi = < 2021.10.08