diff --git a/usr.sbin/pstat/pstat.c b/usr.sbin/pstat/pstat.c
index 519f4d8bb37a..6130e77bd254 100644
--- a/usr.sbin/pstat/pstat.c
+++ b/usr.sbin/pstat/pstat.c
@@ -526,7 +526,7 @@ print_swap(struct kvm_swap *ksw)
 	++nswdev;
 	if (totalflag == 0)
 		print_swap_line(ksw->ksw_devname, ksw->ksw_total,
-		    ksw->ksw_used, ksw->ksw_total,
+		    ksw->ksw_used, ksw->ksw_total - ksw->ksw_used,
 		    (ksw->ksw_used * 100.0) / ksw->ksw_total);
 }