diff --git a/modules/openstack_project/manifests/mirror.pp b/modules/openstack_project/manifests/mirror.pp
index 2203de3405..f0591daa64 100644
--- a/modules/openstack_project/manifests/mirror.pp
+++ b/modules/openstack_project/manifests/mirror.pp
@@ -308,7 +308,7 @@ class openstack_project::mirror (
     # Clean apache cache once an hour, keep size down to 50GiB.
     minute      => '0',
     hour        => '*',
-    command     => 'flock -n /var/run/htcacheclean.lock htcacheclean -n -p /var/cache/apache2/proxy -t -l 51200M > /dev/null',
+    command     => 'flock -n /var/run/htcacheclean.lock htcacheclean -n -p /var/cache/apache2/proxy -t -l 40960M > /dev/null',
     environment => 'PATH=/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin',
     require     => [
        File['/var/cache/apache2/proxy'],