diff --git a/examples/rocketchat/README.md b/examples/rocketchat/README.md
index ff5862e..72b7f64 100644
--- a/examples/rocketchat/README.md
+++ b/examples/rocketchat/README.md
@@ -1,3 +1,20 @@
 # References
 
 - https://github.com/RocketChat/Docker.Official.Image
+
+# Notes
+
+The mongodb container will likely throw a permission error when bein started for the first time.
+
+````
+error: 'An error occurred when creating an index for collection "users: getaddrinfo EAI_AGAIN mongodb',
+  reason: undefined,
+  details: undefined,
+  errorType: 'Meteor.Error'
+````
+
+Therefore, you have to adjust the permissions of the mongodb volume path. For example with the following command:
+
+````
+sudo chmod -R 777 /mnt/docker-volumes/rocketchat
+````