diff --git a/ports/bsd/datetime-init.c b/ports/bsd/datetime-init.c
index ec2e0aa3..810f99dd 100644
--- a/ports/bsd/datetime-init.c
+++ b/ports/bsd/datetime-init.c
@@ -30,6 +30,9 @@
 void datetime_timesync(
     BACNET_DATE *bdate, BACNET_TIME *btime, bool utc)
 {
+    (void)bdate;
+    (void)btime;
+    (void)utc;
     return;
 }
 
diff --git a/ports/win32/datetime-init.c b/ports/win32/datetime-init.c
index eeb418b4..82959465 100644
--- a/ports/win32/datetime-init.c
+++ b/ports/win32/datetime-init.c
@@ -104,6 +104,9 @@ int gettimeofday(struct timeval *tp, void *tzp)
 void datetime_timesync(
     BACNET_DATE *bdate, BACNET_TIME *btime, bool utc)
 {
+    (void)bdate;
+    (void)btime;
+    (void)utc;
     return;
 }