diff --git a/tasks/buster/debian-edu b/tasks/buster/debian-edu
index 30e2b1a8..3fc224f7 100644
--- a/tasks/buster/debian-edu
+++ b/tasks/buster/debian-edu
@@ -3,5 +3,6 @@ debian-edu-config
 debian-edu-install
 debian-edu-profile-udeb
 ltsp-client-builder
+# see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=846006#92 for why the next two are needed
 exim4-daemon-heavy
 sudo-ldap