diff --git a/lib/icinga/checkable-check.cpp b/lib/icinga/checkable-check.cpp
index 5aac602cd..b00674d9f 100644
--- a/lib/icinga/checkable-check.cpp
+++ b/lib/icinga/checkable-check.cpp
@@ -538,6 +538,9 @@ void Checkable::ExecuteCheck()
 			message->Set("jsonrpc", "2.0");
 			message->Set("method", "event::ExecuteCommand");
 
+			double ts = Utility::GetTime();
+			message->Set("ts", ts);
+
 			Host::Ptr host;
 			Service::Ptr service;
 			tie(host, service) = GetHostService(this);
diff --git a/lib/icinga/clusterevents.cpp b/lib/icinga/clusterevents.cpp
index 1651dde71..6d8961f71 100644
--- a/lib/icinga/clusterevents.cpp
+++ b/lib/icinga/clusterevents.cpp
@@ -57,6 +57,9 @@ Dictionary::Ptr ClusterEvents::MakeCheckResultMessage(const Checkable::Ptr& chec
 	message->Set("jsonrpc", "2.0");
 	message->Set("method", "event::CheckResult");
 
+	double ts = Utility::GetTime();
+	message->Set("ts", ts);
+
 	Host::Ptr host;
 	Service::Ptr service;
 	tie(host, service) = GetHostService(checkable);