diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py
index 1c2e344269..be310ba320 100644
--- a/synapse/util/caches/response_cache.py
+++ b/synapse/util/caches/response_cache.py
@@ -25,7 +25,7 @@ class ResponseCache(object):
     """
 
     def __init__(self):
-        self.pending_result_cache = {}  # Request that haven't finished yet.
+        self.pending_result_cache = {}  # Requests that haven't finished yet.
 
     def get(self, key):
         result = self.pending_result_cache.get(key)