diff --git a/conf/local.conf b/conf/local.conf
index c7c113a6..e4235960 100644
--- a/conf/local.conf
+++ b/conf/local.conf
@@ -84,3 +84,11 @@ PREFERRED_PROVIDER_virtual/kernel ?= "linux-lmp"
 #IMAGE_INSTALL_append = " lmp-auto-hostname"
 #LMP_HOSTNAME_MODE = "mac"
 #LMP_HOSTNAME_NETDEVICE = "eth0"
+
+#
+# Automatic docker system prune timer
+#
+# Automatically call docker system prune via a systemd timer. Use
+# DOCKER_PRUNE_ONCALENDAR to configure the desired OnCalendar entry value.
+#IMAGE_INSTALL_append = " docker-auto-prune"
+#DOCKER_PRUNE_ONCALENDAR = "daily"