diff --git a/engine/admin/host_integration.md b/engine/admin/host_integration.md
index 936d68bb50..f890d52e2e 100644
--- a/engine/admin/host_integration.md
+++ b/engine/admin/host_integration.md
@@ -78,7 +78,8 @@ in the `/etc/systemd/system` directory, e.g.
 If you need to pass options to the redis container (such as `--env`),
 then you'll need to use `docker run` rather than `docker start`. This will
 create a new container every time the service is started, which will be stopped
-and removed when the service is stopped.
+and removed when the service is stopped. Make sure you don't use "`-d`" for
+"detached mode". The command run from "`ExecStart`" needs to run in the foreground.
 
     [Service]
     ...
@@ -94,4 +95,4 @@ To start using the service, reload systemd and start the service:
 
 To enable the service at system startup, execute:
 
-    systemctl enable docker-redis_server.service
\ No newline at end of file
+    systemctl enable docker-redis_server.service