1 files changed, 2 insertions, 0 deletions
diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py
index b9a8ca997e..b104f9032c 100644
--- a/synapse/storage/background_updates.py
+++ b/synapse/storage/background_updates.py
@@ -122,6 +122,8 @@ class BackgroundUpdater:
 
     def start_doing_background_updates(self) -> None:
         if self.enabled:
+            # if we start a new background update, not all updates are done.
+            self._all_done = False
             run_as_background_process("background_updates", self.run_background_updates)
 
     async def run_background_updates(self, sleep: bool = True) -> None: