diff --git a/protocol/enttec/dmx-usb-pro/pro.h b/protocol/enttec/dmx-usb-pro/pro.h
index a7a30f1..21d55c9 100644
--- a/protocol/enttec/dmx-usb-pro/pro.h
+++ b/protocol/enttec/dmx-usb-pro/pro.h
@@ -79,20 +79,30 @@ struct MessageData
   /**
    * @brief Initialize MessageData with the appropriate Label
    * @param l Label
-   *
-   * While null messages (label = 0) are not present in the API spec., allow their IO,
-   * perhaps to act as a "ping/echo" to detect emulated devices.
    */
-  MessageData(uint8_t l = 0) : label(l) {};
-
-  size_t streamSize() const override { return 0; };
-  void iStream(std::shared_ptr<bufferstream>) override {};
-  void oStream(std::shared_ptr<bufferstream>) const override{};
+  MessageData(uint8_t l) : label(l) {};
 
   const uint8_t label;                      //!< Message ID label (OpCode)
 };
 
 
+/**
+ * @brief No Op message (Label = 0, no data)
+ *
+ * While null messages (label = 0) are not present in the API spec., allow their IO,
+ * perhaps to act as a "ping/echo" to detect emulated devices.
+ */
+struct MsgNoop
+    : public MessageData
+{
+  MsgNoop() : MessageData(0) {};
+
+  virtual size_t streamSize() const override { return 0; };
+  virtual void iStream(std::shared_ptr<bufferstream>) override {};
+  virtual void oStream(std::shared_ptr<bufferstream>) const override{};
+};
+
+
 /**
  * @brief 1. Reprogram Firmware Request (Label = 1, no data)
  *