diff --git a/api/client-server/definitions/event.json b/api/client-server/definitions/event.json
index 5a8f52f6..98aac21e 100644
--- a/api/client-server/definitions/event.json
+++ b/api/client-server/definitions/event.json
@@ -39,10 +39,6 @@
           "type": "object",
           "description": "Optional. The previous ``content`` for this state. This will be present only for state events appearing in the ``timeline``. If this is not a state event, or there is no previous content, this key will be missing."
         },
-        "replaces_state": {
-          "type": "string",
-          "description": "Optional. The event_id of the previous event for this state. This will be present only for state events appearing in the ``timeline``. If this is not a state event, or there is no previous content, this key will be missing."
-        },
         "transaction_id": {
           "type": "string",
           "description": "Optional. The transaction ID set when this message was sent. This key will only be present for message events sent by the device calling this API."