diff --git a/src/networkpluginserver.cpp b/src/networkpluginserver.cpp
index a012ee871bce221c7883d6482307f308b21f3021..8e80e321cf9c4070014a68b7370aeecc65cd53ae 100644
--- a/src/networkpluginserver.cpp
+++ b/src/networkpluginserver.cpp
@@ -708,6 +708,10 @@ void NetworkPluginServer::handleConvMessageAckPayload(const std::string &data) {
 	if (!user)
 		return;
 
+	if (payload.id().empty()) {
+		LOG4CXX_WARN(logger, "Received message ack with empty ID, not forwarding to XMPP.");
+		return;
+	}
 
 	boost::shared_ptr<Swift::Message> msg(new Swift::Message());
 	msg->addPayload(boost::make_shared<Swift::DeliveryReceipt>(payload.id()));