1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py
index b68f9fe0d4..a6c60888e5 100644
--- a/synapse/util/caches/response_cache.py
+++ b/synapse/util/caches/response_cache.py
@@ -38,7 +38,7 @@ class ResponseCache(object):
         self.timeout_sec = timeout_ms / 1000.0
 
         self._name = name
-        self._metrics = register_cache("response_cache", name, self)
+        self._metrics = register_cache("response_cache", name, self, resizable=False)
 
     def size(self):
         return len(self.pending_result_cache)