diff --git a/net_io.c b/net_io.c
index c91ed9b..5148b6a 100644
--- a/net_io.c
+++ b/net_io.c
@@ -571,7 +571,7 @@ static void modesSendSBSOutput(struct modesMessage *mm, struct aircraft *a) {
 
     // Fields 7 & 8 are the message reception time and date
     p += sprintf(p, "%04d/%02d/%02d,", (stTime_receive.tm_year+1900),(stTime_receive.tm_mon+1), stTime_receive.tm_mday);
-    p += sprintf(p, "%02d:%02d:%02d.%03u,", stTime_receive.tm_hour, stTime_receive.tm_min, stTime_receive.tm_sec, (unsigned) (mm->sysTimestampMsg / 1000));
+    p += sprintf(p, "%02d:%02d:%02d.%03u,", stTime_receive.tm_hour, stTime_receive.tm_min, stTime_receive.tm_sec, (unsigned) (mm->sysTimestampMsg % 1000));
 
     // Fields 9 & 10 are the current time and date
     p += sprintf(p, "%04d/%02d/%02d,", (stTime_now.tm_year+1900),(stTime_now.tm_mon+1), stTime_now.tm_mday);