diff --git a/fern/definition/lists.yml b/fern/definition/lists.yml
index 10245c9..f8d957e 100644
--- a/fern/definition/lists.yml
+++ b/fern/definition/lists.yml
@@ -38,6 +38,9 @@ types:
       created_at:
         type: datetime
         docs: Time at which entry was created.
+      read_only:
+        type: optional<boolean>
+        docs: Whether the entry is read-only and cannot be deleted via the API.
 
   ListEntry:
     extends: ListEntryBase