diff --git a/plinth/modules/upgrades/data/etc/apt/preferences.d/50freedombox3.pref b/plinth/modules/upgrades/data/etc/apt/preferences.d/50freedombox3.pref
index b4a19265b..918f3408e 100644
--- a/plinth/modules/upgrades/data/etc/apt/preferences.d/50freedombox3.pref
+++ b/plinth/modules/upgrades/data/etc/apt/preferences.d/50freedombox3.pref
@@ -14,3 +14,8 @@ Explanation: matrix-synapse >= 1.2 requires python3-service-identity >= 18.1
 Package: python3-service-identity
 Pin: release a=buster-backports
 Pin-Priority: 500
+
+Explanation: matrix-synapse >= 1.5 requires python3-typing-extensions >= 3.7.4
+Package: python3-typing-extensions
+Pin: release a=buster-backports
+Pin-Priority: 500