diff --git a/bacnet-stack/demo/timesync/Makefile b/bacnet-stack/demo/timesync/Makefile
index 37b7b747..39f0980c 100644
--- a/bacnet-stack/demo/timesync/Makefile
+++ b/bacnet-stack/demo/timesync/Makefile
@@ -50,7 +50,7 @@ SRCS = main.c \
        $(BACNET_ROOT)/bacstr.c \
        $(BACNET_ROOT)/bactext.c \
        $(BACNET_ROOT)/indtext.c \
-       $(BACNET_ROOT)/bigend.c \
+       $(BACNET_ROOT)/datetime.c \
        $(BACNET_ROOT)/whois.c \
        $(BACNET_ROOT)/iam.c \
        $(BACNET_ROOT)/whohas.c \
diff --git a/bacnet-stack/demo/timesync/makefile.b32 b/bacnet-stack/demo/timesync/makefile.b32
index e40a54c2..2b3819b6 100644
--- a/bacnet-stack/demo/timesync/makefile.b32
+++ b/bacnet-stack/demo/timesync/makefile.b32
@@ -49,7 +49,7 @@ SRCS = main.c \
        $(BACNET_ROOT)\bacstr.c \
        $(BACNET_ROOT)\bactext.c \
        $(BACNET_ROOT)\indtext.c \
-       $(BACNET_ROOT)\bigend.c \
+       $(BACNET_ROOT)\datetime.c \
        $(BACNET_ROOT)\whois.c \
        $(BACNET_ROOT)\iam.c \
        $(BACNET_ROOT)\whohas.c \