1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/util/caches/stream_change_cache.py b/synapse/util/caches/stream_change_cache.py

index d8253bd942..2079ca789c 100644
--- a/synapse/util/caches/stream_change_cache.py
+++ b/synapse/util/caches/stream_change_cache.py
@@ -115,7 +115,7 @@ class StreamChangeCache:
         """
         new_size = math.floor(self._original_max_size * factor)
         if new_size != self._max_size:
-            self.max_size = new_size
+            self._max_size = new_size
             self._evict()
             return True
         return False