1 files changed, 2 insertions, 0 deletions
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 0e323846fa..601a8338eb 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -1328,6 +1328,8 @@ account_threepid_delegates:
 # By default, any room aliases included in this list will be created
 # as a publicly joinable room when the first user registers for the
 # homeserver. This behaviour can be customised with the settings below.
+# If the room already exists, make certain it is a publicly joinable
+# room. The join rule of the room must be set to 'public'.
 #
 #auto_join_rooms:
 #  - "#example:example.com"