diff --git a/requirements.txt b/requirements.txt
index 23c85f7a..e2c93c97 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 # Base requirements for ssm
 
 argo-ams-library
+certifi<2020.4.5.2  # Used by AMS (via requests), 2020.4.5.2 dropped support for Python 2
 stomp.py<5.0.0
 python-daemon<=2.3.0  # 2.3.1 dropped support for Python 2
 python-ldap<3.4.0  # python-ldap-3.4.0 dropped support for Python 2