1 files changed, 2 insertions, 0 deletions
diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index b013a3918c..8b098ad48d 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -26,6 +26,8 @@ class ExperimentalConfig(Config):
 
         # Whether to enable experimental MSC1849 (aka relations) support
         self.msc1849_enabled = config.get("experimental_msc1849_support_enabled", True)
+        # MSC3440 (thread relation)
+        self.msc3440_enabled: bool = experimental.get("msc3440_enabled", False)
 
         # MSC3026 (busy presence state)
         self.msc3026_enabled: bool = experimental.get("msc3026_enabled", False)