2 files changed, 2 insertions, 1 deletions
diff --git a/changelog.d/17176.misc b/changelog.d/17176.misc
new file mode 100644
index 0000000000..cc9f2a5202
--- /dev/null
+++ b/changelog.d/17176.misc
@@ -0,0 +1 @@
+Log exceptions when failing to auto-join new user according to the `auto_join_rooms` option.
\ No newline at end of file
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index e48e70db04..c200e29569 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -590,7 +590,7 @@ class RegistrationHandler:
                 # moving away from bare excepts is a good thing to do.
                 logger.error("Failed to join new user to %r: %r", r, e)
             except Exception as e:
-                logger.error("Failed to join new user to %r: %r", r, e)
+                logger.error("Failed to join new user to %r: %r", r, e, exc_info=True)
 
     async def _auto_join_rooms(self, user_id: str) -> None:
         """Automatically joins users to auto join rooms - creating the room in the first place