diff --git a/bacnet-stack/include/bip.h b/bacnet-stack/include/bip.h
index 3990582e..a9c4e331 100644
--- a/bacnet-stack/include/bip.h
+++ b/bacnet-stack/include/bip.h
@@ -84,6 +84,7 @@ extern "C" {
     /* use network byte order for setting */
     void bip_set_port(
         uint16_t port);
+    bool bip_port_changed(void);
     /* returns network byte order */
     uint16_t bip_get_port(
         void);