1 files changed, 2 insertions, 0 deletions
diff --git a/develop/modules/password_auth_provider_callbacks.html b/develop/modules/password_auth_provider_callbacks.html
index cd68b32bf9..0a767725e2 100644
--- a/develop/modules/password_auth_provider_callbacks.html
+++ b/develop/modules/password_auth_provider_callbacks.html
@@ -180,6 +180,8 @@ the client.</p>
 <code>/login</code> request. If the module doesn't wish to return a callback, it must return <code>None</code>
 instead.</p>
 <p>If the authentication is unsuccessful, the module must return <code>None</code>.</p>
+<p>Note that the user is not automatically registered, the <code>register_user(..)</code> method of
+the <a href="writing_a_module.html">module API</a> can be used to lazily create users.</p>
 <p>If multiple modules register an auth checker for the same login type but with different
 fields, Synapse will refuse to start.</p>
 <p>If multiple modules register an auth checker for the same login type with the same fields,