diff --git a/kernel/sys.c b/kernel/sys.c
index 481611f..ddf8155 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1605,7 +1605,7 @@
 	unsigned long maxrss = 0;
 
 	memset((char *) r, 0, sizeof *r);
-	utime = stime = cputime_zero;
+	utime = stime = 0;
 
 	if (who == RUSAGE_THREAD) {
 		task_times(current, &utime, &stime);
@@ -1635,8 +1635,8 @@
 
 		case RUSAGE_SELF:
 			thread_group_times(p, &tgutime, &tgstime);
-			utime = cputime_add(utime, tgutime);
-			stime = cputime_add(stime, tgstime);
+			utime += tgutime;
+			stime += tgstime;
 			r->ru_nvcsw += p->signal->nvcsw;
 			r->ru_nivcsw += p->signal->nivcsw;
 			r->ru_minflt += p->signal->min_flt;