diff --git a/actions/upgrades b/actions/upgrades
index 49242c31e..ca7001826 100755
--- a/actions/upgrades
+++ b/actions/upgrades
@@ -63,6 +63,11 @@ Explanation: python3-twisted requires matching version of python3-twisted-bin
 Package: python3-twisted-bin
 Pin: release a=buster-backports
 Pin-Priority: 500
+
+Explanation: matrix-synapse >= 1.16 requires python3-attr >= 19.1.0~
+Package: python3-attr
+Pin: release a=buster-backports
+Pin-Priority: 500
 '''
 
 
diff --git a/plinth/modules/upgrades/__init__.py b/plinth/modules/upgrades/__init__.py
index b75c6f1c2..0edf17e7b 100644
--- a/plinth/modules/upgrades/__init__.py
+++ b/plinth/modules/upgrades/__init__.py
@@ -17,7 +17,7 @@ from plinth import cfg, glib, menu
 
 from .manifest import backup  # noqa, pylint: disable=unused-import
 
-version = 4
+version = 5
 
 is_essential = True