diff --git a/plugins/yampl-zmq/src/ServerSocket.cpp b/plugins/yampl-zmq/src/ServerSocket.cpp
index df1ff18..559a31a 100644
--- a/plugins/yampl-zmq/src/ServerSocket.cpp
+++ b/plugins/yampl-zmq/src/ServerSocket.cpp
@@ -43,11 +43,11 @@ void ServerSocket::sendMessage(zmq::message_t &message, const std::string *peerI
         zmq::message_t address(peerId->size() + 1);
         memcpy((void*)address.data(), peerId->c_str(), peerId->size() + 1);
 
-        if(m_socket->send(address, ZMQ_SNDMORE | ZMQ_DONTWAIT) == -1)
+        if(static_cast<int>(m_socket->send(address, ZMQ_SNDMORE | ZMQ_DONTWAIT)) == -1)
           throw UnroutableException();
       }
       else {
-        if(m_socket->send(*m_lastAddress, ZMQ_SNDMORE | ZMQ_DONTWAIT) == -1)
+        if(static_cast<int>(m_socket->send(*m_lastAddress, ZMQ_SNDMORE | ZMQ_DONTWAIT)) == -1)
           throw UnroutableException();
       }
     }