diff --git a/bacnet-stack/ports/pic18f6720/h_rp.c b/bacnet-stack/ports/pic18f6720/h_rp.c
index 012a525e..01df2e86 100644
--- a/bacnet-stack/ports/pic18f6720/h_rp.c
+++ b/bacnet-stack/ports/pic18f6720/h_rp.c
@@ -38,6 +38,7 @@
 /* demo objects */
 #include "device.h"
 #include "ai.h"
+#include "av.h"
 #include "bi.h"
 #include "bv.h"