diff --git a/api/client-server/v2_alpha/definitions/sync_filter.json b/api/client-server/v2_alpha/definitions/sync_filter.json
index 4ad3aa82..b4f87e5f 100644
--- a/api/client-server/v2_alpha/definitions/sync_filter.json
+++ b/api/client-server/v2_alpha/definitions/sync_filter.json
@@ -39,7 +39,7 @@
     "event_fields": {
       "type": "array",
       "description":
-        "List of event fields to include. If this list is absent then all fields are included. The entries may include '.' charaters to indicate sub-fields. So ['content.body'] will include the 'body' field of the 'content' object. A server may include more fields than were requested.",
+        "List of event fields to include. If this list is absent then all fields are included. The entries may include '.' charaters to indicate sub-fields. So ['content.body'] will include the 'body' field of the 'content' object. A literal '.' character in a field name may be escaped using a '\\'. A server may include more fields than were requested.",
       "items": {
         "type": "string"
       }