diff --git a/sys/sys/time.h b/sys/sys/time.h
--- a/sys/sys/time.h
+++ b/sys/sys/time.h
@@ -355,9 +355,9 @@
 static __inline sbintime_t
 tstosbt_sat(struct timespec _ts)
 {
-	if (_ts.tv_sec > SBT_MAX >> 32)
+	if (_ts.tv_sec >= SBT_MAX >> 32)
 		return (SBT_MAX);
-	if (_ts.tv_sec < -(SBT_MAX >> 32) - 1)
+	if (_ts.tv_sec <= -(SBT_MAX >> 32) - 1)
 		return (-SBT_MAX - 1);
 	return (tstosbt(_ts));
 }
@@ -382,9 +382,9 @@
 static __inline sbintime_t
 tvtosbt_sat(struct timeval _tv)
 {
-	if (_tv.tv_sec > SBT_MAX >> 32)
+	if (_tv.tv_sec >= SBT_MAX >> 32)
 		return (SBT_MAX);
-	if (_tv.tv_sec < -(SBT_MAX >> 32) - 1)
+	if (_tv.tv_sec <= -(SBT_MAX >> 32) - 1)
 		return (-SBT_MAX - 1);
 	return (tvtosbt(_tv));
 }