diff --git a/vscp/vscp_transport.c b/vscp/vscp_transport.c
index 9f2d7fca..39b4ab42 100644
--- a/vscp/vscp_transport.c
+++ b/vscp/vscp_transport.c
@@ -48,6 +48,7 @@
 #include "vscp_tp_adapter.h"
 #include "vscp_config.h"
 #include "vscp_util.h"
+#include "vscp_class_l1.h"
 
 /*******************************************************************************
     COMPILER SWITCHES