diff --git a/stretch/preferences.d/stretch-backports b/stretch/preferences.d/stretch-backports
index 0c83837..655baa1 100644
--- a/stretch/preferences.d/stretch-backports
+++ b/stretch/preferences.d/stretch-backports
@@ -2,7 +2,95 @@ Package: certbot
 Pin: release a=stretch-backports
 Pin-Priority: 900
 
+Package: python3-acme
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-asn1crypto
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
 Package: python3-certbot
 Pin: release a=stretch-backports
 Pin-Priority: 900
 
+Package: python3-cffi-backend
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-chardet
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-configargparse
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-configobj
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-cryptography
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-future
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-idna
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-josepy
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-mock
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-openssl
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-parsedatetime
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-pbr
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-requests
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-requests-toolbelt
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-rfc3339
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-six
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-tz
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-urllib3
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-zope.component
+Pin: release a=stretch-backports
+Pin-Priority: 900
+
+Package: python3-zope.event
+Pin: release a=stretch-backports
+Pin-Priority: 900
+