diff --git a/doc/upstream-training/accounts.rst b/doc/upstream-training/accounts.rst
index b5678b9c..e5166985 100644
--- a/doc/upstream-training/accounts.rst
+++ b/doc/upstream-training/accounts.rst
@@ -73,6 +73,11 @@ Sign Up
 #. You will be prompted to select a username. You can enter the same one you
    did for launchpad, or something else.
 
+.. note::
+
+   Choose and type your username carefully.
+   Once it is set, you cannot change the username.
+
 .. note::
 
   From here on out when you sign into Gerrit, you'll be prompted to enter your