diff --git a/bacnet-stack/demo/object/ao.c b/bacnet-stack/demo/object/ao.c
index 9dbd600b..43835c4a 100644
--- a/bacnet-stack/demo/object/ao.c
+++ b/bacnet-stack/demo/object/ao.c
@@ -34,6 +34,7 @@
 #include "bacapp.h"
 #include "config.h"     /* the custom stuff */
 #include "wp.h"
+#include "ao.h"
 
 #define MAX_ANALOG_OUTPUTS 4
 
diff --git a/bacnet-stack/include/ao.h b/bacnet-stack/include/ao.h
index 25254d03..a14174d8 100644
--- a/bacnet-stack/include/ao.h
+++ b/bacnet-stack/include/ao.h
@@ -57,7 +57,7 @@ extern "C" {
         unsigned priority);
     bool Analog_Output_Present_Value_Relinquish(
         uint32_t object_instance,
-        int priority);
+        unsigned priority);
 
 
     int Analog_Output_Encode_Property_APDU(