diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index f2dfd49b0777..89b076e42bf6 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -84,3 +84,6 @@ def read_config(self, config: JsonDict, **kwargs: Any) -> None:
 
         # MSC3772: A push rule for mutual relations.
         self.msc3772_enabled: bool = experimental.get("msc3772_enabled", False)
+
+        # MSC2246 (async media uploads)
+        self.msc2246_enabled: bool = experimental.get("msc2246_enabled", False)