diff --git a/docs/ocis/getting-started.md b/docs/ocis/getting-started.md
index b4610bcb3..a1c196e46 100644
--- a/docs/ocis/getting-started.md
+++ b/docs/ocis/getting-started.md
@@ -35,6 +35,10 @@ chmod +x ocis
 
 The default primary storage location is `/var/tmp/ocis`. You can change that value by configuration.
 
+{{< hint warning >}}
+oCIS by default relies on Multicast DNS (mDNS), usually via avahi-daemon. If your system has a firewall, make sure mDNS is allowed in your active zone.
+{{< /hint >}}
+
 
 ### Docker