diff --git a/live-build/ubuntu-cpc/hooks/030-root-tarball.binary b/live-build/ubuntu-cpc/hooks/030-root-tarball.binary
index fd818595..28d920ce 100755
--- a/live-build/ubuntu-cpc/hooks/030-root-tarball.binary
+++ b/live-build/ubuntu-cpc/hooks/030-root-tarball.binary
@@ -26,3 +26,4 @@ umount "binary/boot/filesystem.dir/proc"
 umount "binary/boot/filesystem.dir/sys"
 umount "binary/boot/filesystem.dir/dev/pts"
 umount "binary/boot/filesystem.dir/dev"
+umount "binary/boot/filesystem.dir/tmp"