diff --git a/DBus-service.md b/DBus-service.md
index b41ec77..075c0ff 100644
--- a/DBus-service.md
+++ b/DBus-service.md
@@ -222,3 +222,10 @@ Environment variable `DBUS_SESSION_BUS_ADDRESS` needs to be set. See [#394](http
 Under Mac OSX, the environment variable `DBUS_LAUNCHD_SESSION_BUS_SOCKET` needs to be set (see above). This can be done by issuing the command
 
 ```export DBUS_LAUNCHD_SESSION_BUS_SOCKET=$(launchctl getenv DBUS_LAUNCHD_SESSION_BUS_SOCKET)```
+
+#### DBus exception when calling dbus-send via Cron under Ubuntu
+      Failed to open connection to "session" message bus: Unable to autolaunch a dbus-daemon without a $DISPLAY for X11
+
+Script started via Cron must export environment variable `DBUS_SESSION_BUS_ADDRESS` before calling dbus-send 
+
+```export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(id -u)/bus```
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