Bug: https://bugs.gentoo.org/594990

--- a/libmessageio/tcpmessageserverconnection.cc
+++ b/libmessageio/tcpmessageserverconnection.cc
@@ -91,7 +91,7 @@
 }
 
 
-void TCPMessageServerConnection::queueAndSendMessageSlot(Message & message)
+void TCPMessageServerConnection::queueAndSendMessageSlot(const Message & message)
 {
 
   if (sendQueue.size()<maxSendQueueSize)
--- a/libmessageio/tcpmessageserverconnection.h
+++ b/libmessageio/tcpmessageserverconnection.h
@@ -32,7 +32,7 @@
   void handleReadMessageSize(const boost::system::error_code& err, size_t length);
   void handleReadMessage(const boost::system::error_code& err, size_t length);
 
-  void queueAndSendMessageSlot(Message & message);
+  void queueAndSendMessageSlot(const Message & message);
   std::list<Message>  sendQueue;
   bool sendQueueCurrentlySending;
   void startNewTransmission();