1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/api/events/__init__.py b/synapse/api/events/__init__.py

index 910c990b33..d68629209d 100644
--- a/synapse/api/events/__init__.py
+++ b/synapse/api/events/__init__.py
@@ -59,7 +59,7 @@ class SynapseEvent(JsonEncodedObject):
         "age_ts",
         "prev_content",
         "prev_state",
-        "pruned",
+        "pruned_because",
     ]
 
     internal_keys = [