diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 2d1291b9f8..b8587f4545 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -545,6 +545,7 @@ class SyncHandler:
                         )
                     )
 
+                cache_context.should_cache = False
                 return SyncResult.empty(
                     since_token, one_time_keys_count, unused_fallback_key_types
                 )