diff --git a/src/schema/provenance_schema.yaml b/src/schema/provenance_schema.yaml
index 447f0078..43c53dad 100644
--- a/src/schema/provenance_schema.yaml
+++ b/src/schema/provenance_schema.yaml
@@ -976,6 +976,7 @@ ENTITIES:
       direct_ancestor:
         type: json_string # dict
         generated: true
+        immutable: true
         transient: true
         indexed: false
         on_read_trigger: get_sample_direct_ancestor