diff --git a/bacnet-stack/ports/bdk-atxx4-mstp/Makefile b/bacnet-stack/ports/bdk-atxx4-mstp/Makefile
index 20014832..060311eb 100644
--- a/bacnet-stack/ports/bdk-atxx4-mstp/Makefile
+++ b/bacnet-stack/ports/bdk-atxx4-mstp/Makefile
@@ -61,6 +61,7 @@ CSRC = main.c \
 	led.c \
 	eeprom.c \
 	seeprom.c \
+	watchdog.c \
 	dlmstp.c \
 	test.c \
 	bacnet.c \