diff --git a/bacnet-stack/bacapp.c b/bacnet-stack/bacapp.c
index 72874f75..87ce99f4 100644
--- a/bacnet-stack/bacapp.c
+++ b/bacnet-stack/bacapp.c
@@ -34,6 +34,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <string.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include "bacenum.h"
 #include "bacdcode.h"