diff --git a/vnc/vncclientthread.h b/vnc/vncclientthread.h
--- a/vnc/vncclientthread.h
+++ b/vnc/vncclientthread.h
@@ -170,7 +170,7 @@
     void cuttext(const char *text, int textlen);
     char *passwdHandler();
     rfbCredential *credentialHandler(int credentialType);
-    void outputHandler(const char *format, ...);
+    void outputHandler(const char *format, va_list args);
 
     QImage m_image;
     rfbClient *cl;
diff --git a/vnc/vncclientthread.cpp b/vnc/vncclientthread.cpp
--- a/vnc/vncclientthread.cpp
+++ b/vnc/vncclientthread.cpp
@@ -259,16 +259,11 @@
     return cred;
 }
 
-void VncClientThread::outputHandler(const char *format, ...)
+void VncClientThread::outputHandler(const char *format, va_list args)
 {
-    va_list args;
-    va_start(args, format);
-
     QString message;
     message.vsprintf(format, args);
 
-    va_end(args);
-
     message = message.trimmed();
 
     qCDebug(KRDC) << message;