diff --git a/spec/namespaces/indices.yaml b/spec/namespaces/indices.yaml
index cdcaaf29..7b04c98f 100644
--- a/spec/namespaces/indices.yaml
+++ b/spec/namespaces/indices.yaml
@@ -1831,6 +1831,7 @@ paths:
       operationId: indices.get_upgrade.1
       x-operation-group: indices.get_upgrade
       x-version-added: '1.0'
+      x-version-deprecated: '1.0'
       description: The `_upgrade` API is no longer useful and will be removed.
       externalDocs:
         url: https://opensearch.org/docs/latest
@@ -1846,6 +1847,7 @@ paths:
       operationId: indices.upgrade.1
       x-operation-group: indices.upgrade
       x-version-added: '1.0'
+      x-version-deprecated: '1.0'
       description: The `_upgrade` API is no longer useful and will be removed.
       externalDocs:
         url: https://opensearch.org/docs/latest
diff --git a/tests/default/indices/upgrade.yaml b/tests/default/indices/upgrade.yaml
index 46d81bb0..281f9402 100644
--- a/tests/default/indices/upgrade.yaml
+++ b/tests/default/indices/upgrade.yaml
@@ -36,5 +36,22 @@ chapters:
     method: GET
     parameters:
       index: [movies]
+    response:
+      status: 200
+
+  - synopsis: Trigger upgrade (POST).
+    path: /_upgrade
+    method: POST
+    request:
+      payload:
+        allow_no_indices: false
+        expand_wildcards: closed
+        ignore_unavailable: false
+    response:
+      status: 200
+
+  - synopsis: Check upgrade status (GET).
+    path: /_upgrade
+    method: GET
     response:
       status: 200
\ No newline at end of file