diff --git a/lib/icinga/clusterevents.cpp b/lib/icinga/clusterevents.cpp
index db8102729..6c54be340 100644
--- a/lib/icinga/clusterevents.cpp
+++ b/lib/icinga/clusterevents.cpp
@@ -445,6 +445,7 @@ void ClusterEvents::AcknowledgementSetHandler(const Checkable::Ptr& checkable,
 	params->Set("comment", comment);
 	params->Set("acktype", type);
 	params->Set("notify", notify);
+	params->Set("persistent", persistent);
 	params->Set("expiry", expiry);
 
 	Dictionary::Ptr message = new Dictionary();