diff --git a/src/ophyd_async/core/async_status.py b/src/ophyd_async/core/async_status.py
index 4ee0e4eb03..474dd1eb15 100644
--- a/src/ophyd_async/core/async_status.py
+++ b/src/ophyd_async/core/async_status.py
@@ -118,8 +118,10 @@ async def _notify_watchers_from(self, iterator: AsyncIterator[WatcherUpdate[T]])
         async for update in iterator:
             if self._timeout and time.monotonic() > self._timeout:
                 raise TimeoutError()
-            self._last_update = replace(
-                update, time_elapsed=time.monotonic() - self._start
+            self._last_update = (
+                update
+                if update.time_elapsed is None
+                else replace(update, time_elapsed=time.monotonic() - self._start)
             )
             for watcher in self._watchers:
                 self._update_watcher(watcher, self._last_update)