diff --git a/platform/qt/dmxwidget/dmxwidget.cpp b/platform/qt/dmxwidget/dmxwidget.cpp
index 7acdf3c..751bef7 100644
--- a/platform/qt/dmxwidget/dmxwidget.cpp
+++ b/platform/qt/dmxwidget/dmxwidget.cpp
@@ -126,7 +126,8 @@ void DmxWidget::sendMessage(std::shared_ptr<ENTTEC::Pro::MessageData> msg) const
   *stream << ENTTEC::Pro::START_DELIMITER;
   *stream << msg->label;
   *stream << length;
-  *stream << msg;
+  if (length)
+    *stream << msg;
   *stream << ENTTEC::Pro::END_DELIMITER;
 
   port_->write(reinterpret_cast<char*>(buffer), sizeof(buffer));