--- mosquitto-1.6.8.orig/mosquitto.conf
+++ mosquitto-1.6.8/mosquitto.conf
@@ -985,4 +985,4 @@
 # alphabetical order, with capital letters ordered first. If this option is
 # given multiple times, all of the files from the first instance will be
 # processed before the next instance. See the man page for examples.
-#include_dir
+include_dir /etc/mosquitto/conf.d