diff --git a/README.md b/README.md
index 775282f..d3c5917 100644
--- a/README.md
+++ b/README.md
@@ -99,7 +99,7 @@ $ sudo apt install -y sshpass
 $ ansible-playbook -vi inventory -k -l all playbooks/base.yml
 ```
 
-If that does not work, add it to the `~/.ssh/authorized_keys` in the `root` home folder on every one of your virtual machines.
+If that does not work, add it to the `~/.ssh/authorized_keys` in the `root` home folder on every one of your virtual machines, make sure the `authorized_keys` file has `600` permissions. If the permissions are too wide then sshd will refuse to use it.
 
 While you are at it I would recommend you install docker as well using the `docker.yml` playbook