diff --git a/bacnet-stack/demo/object/device.c b/bacnet-stack/demo/object/device.c
index 2a9053d0..036342ef 100644
--- a/bacnet-stack/demo/object/device.c
+++ b/bacnet-stack/demo/object/device.c
@@ -98,6 +98,7 @@ static const int Device_Properties_Optional[] = {
     PROP_DAYLIGHT_SAVINGS_STATUS,
     PROP_PROTOCOL_CONFORMANCE_CLASS,
     PROP_LOCATION,
+    PROP_ACTIVE_COV_SUBSCRIPTIONS,
     -1
 };