diff --git a/changelog.d/19267.bugfix b/changelog.d/19267.bugfix
new file mode 100644
index 000000000..6c7ed750e
--- /dev/null
+++ b/changelog.d/19267.bugfix
@@ -0,0 +1 @@
+Fix bug where `Duration` was logged incorrectly.
diff --git a/synapse/appservice/scheduler.py b/synapse/appservice/scheduler.py
index befb4ae44..c3a83d140 100644
--- a/synapse/appservice/scheduler.py
+++ b/synapse/appservice/scheduler.py
@@ -506,7 +506,7 @@ class _Recoverer:
 
     def recover(self) -> None:
         delay = Duration(seconds=2**self.backoff_counter)
-        logger.info("Scheduling retries on %s in %fs", self.service.id, delay)
+        logger.info("Scheduling retries on %s in %fs", self.service.id, delay.as_secs())
         self.scheduled_recovery = self.clock.call_later(
             delay,
             self.hs.run_as_background_process,