diff --git a/deflect/ServerWorker.cpp b/deflect/ServerWorker.cpp
index 5041f06..2352bfe 100644
--- a/deflect/ServerWorker.cpp
+++ b/deflect/ServerWorker.cpp
@@ -84,7 +84,7 @@ ServerWorker::~ServerWorker()
     if( !_streamId.isEmpty( ))
         emit removeStreamSource( _streamId, _sourceId );
 
-    if( _tcpSocket->state() == QAbstractSocket::ConnectedState )
+    if( _isConnected( ))
         _sendQuit();
 
     delete _tcpSocket;
@@ -138,7 +138,7 @@ void ServerWorker::_processMessages()
     _tcpSocket->flush();
 
     // Finish reading messages from the socket if connection closed
-    if( _tcpSocket->state() != QAbstractSocket::ConnectedState )
+    if( !_isConnected( ))
     {
         while( _tcpSocket->bytesAvailable() >= headerSize )
             _receiveMessage();
@@ -321,8 +321,13 @@ bool ServerWorker::_send( const MessageHeader& messageHeader )
 void ServerWorker::_flushSocket()
 {
     _tcpSocket->flush();
-    while( _tcpSocket->bytesToWrite() > 0 )
+    while( _tcpSocket->bytesToWrite() > 0 && _isConnected( ))
         _tcpSocket->waitForBytesWritten();
 }
 
+bool ServerWorker::_isConnected() const
+{
+    return _tcpSocket->state() == QTcpSocket::ConnectedState;
+}
+
 }
diff --git a/deflect/ServerWorker.h b/deflect/ServerWorker.h
index 75a04a9..d127219 100644
--- a/deflect/ServerWorker.h
+++ b/deflect/ServerWorker.h
@@ -112,6 +112,7 @@ private slots:
     void _sendQuit();
     bool _send( const MessageHeader& messageHeader );
     void _flushSocket();
+    bool _isConnected() const;
 };
 
 }
diff --git a/doc/Changelog.md b/doc/Changelog.md
index 4d4f594..8a6cdc1 100644
--- a/doc/Changelog.md
+++ b/doc/Changelog.md
@@ -5,6 +5,9 @@ Changelog {#Changelog}
 
 ### 0.12.0 (git master)
 
+* [115](https://github.com/BlueBrain/Deflect/pull/115):
+  Bugfix for possible endless loop of warnings in ServerWorker::_flushSocket():
+  "QAbstractSocket::waitForBytesWritten() is not allowed in UnconnectedState"
 * [114](https://github.com/BlueBrain/Deflect/pull/114):
   QmlStreamer: added support for keyboard events