diff --git a/rc/bin/dontkill b/rc/bin/dontkill
index 3dc79b940..1cdbad721 100755
--- a/rc/bin/dontkill
+++ b/rc/bin/dontkill
@@ -6,6 +6,9 @@ if (! ~ $#* 1) {
 	exit usage
 }
 # see /sys/src/9/port/proc.c:/^killbig
-pids=`{psu | awk '$NF ~ /'$1'/ {print $2}'}
-~ $#pids 0 || {for(p in /proc/^$pids^/ctl){chmod +w $p; echo noswap >$p; chmod -w $p}} >/dev/null >[2=1]
-
+psu | awk '$NF ~ /'$1'/ {
+c="/proc/"$2"/ctl"
+print "chmod +w "c
+print "echo noswap >"c
+print "chmod -w "c
+}' | rc >/dev/null >[2=1]