diff --git a/docs/cookbook/container/.gitignore b/docs/cookbook/container/.gitignore
index 6cc4ebd..c444069 100644
--- a/docs/cookbook/container/.gitignore
+++ b/docs/cookbook/container/.gitignore
@@ -3,6 +3,7 @@ debootstrap
 debian
 libs
 simple
+*.code
 *.dockjson
 *.fakeroot
 *.fs
@@ -11,6 +12,7 @@ simple
 *.initrd
 *.layer
 *.list
+*.out
 *.runkvm
 *.runlocal
 *.rundocker
diff --git a/docs/cookbook/container/clean.do b/docs/cookbook/container/clean.do
index 24431d6..8899f0b 100644
--- a/docs/cookbook/container/clean.do
+++ b/docs/cookbook/container/clean.do
@@ -1,6 +1,6 @@
 rm -rf *~ .*~ simple libs debian \
 	*.fs debian.fakeroot *.gz \
-	*.dockjson *.image *.image.gz *.initrd \
-	*.layer *.list \
+	*.code *.dockjson *.image *.image.gz *.initrd \
+	*.out *.layer *.list \
 	*.runkvm *.runlocal *.rundocker \
 	*.sha256
diff --git a/docs/cookbook/container/default.runkvm.do b/docs/cookbook/container/default.runkvm.do
index 287ed3a..2b3ef0c 100644
--- a/docs/cookbook/container/default.runkvm.do
+++ b/docs/cookbook/container/default.runkvm.do
@@ -1,7 +1,7 @@
 ./need.sh python kvm busybox
 
 redo-ifchange "$2.initrd" memcalc.py
-rm -f "$3.out" "$3.code"
+rm -f "$1.out" "$1.code"
 
 # Linux only allows an initrd of size < 50% of RAM,
 # so set a RAM amount based on the initrd size.
@@ -16,18 +16,17 @@ kvm \
 	-no-reboot \
 	-display none \
 	-chardev stdio,mux=on,id=char0 \
-	-chardev file,id=char1,path="$3.out" \
-	-chardev file,id=char2,path="$3.code" \
+	-chardev file,id=char1,path="$1.out" \
+	-chardev file,id=char2,path="$1.code" \
 	-serial chardev:char0 \
 	-serial chardev:char1 \
 	-serial chardev:char2 >&2
-read rv <$3.code || true
+read rv <$1.code || true
 [ -z "$rv" ] && exit 99
 if [ "$rv" -eq 0 ]; then
-	sed -e 's/\r//g' "$3.out" >$3
+	sed -e 's/\r//g' "$1.out" >$3
 	echo "ok." >&2
 else
 	echo "kvm program returned error: $rv" >&2
 fi
-rm -f "$3.out" "$3.code"
 exit "$rv"