diff --git a/synapse/util/caches/dictionary_cache.py b/synapse/util/caches/dictionary_cache.py
index e60c81cdf6..1c62910b05 100644
--- a/synapse/util/caches/dictionary_cache.py
+++ b/synapse/util/caches/dictionary_cache.py
@@ -154,8 +154,7 @@ class DictionaryCache(Generic[KT, DKT, DV]):
         ] = LruCache(
             max_size=max_entries,
             cache_name=name,
-            # TODO
-            # cache_manager=cache_manager,
+            cache_manager=cache_manager,
             cache_type=TreeCache,
             size_callback=len,
         )