diff --git a/vertexai/preview/rag/rag_data.py b/vertexai/preview/rag/rag_data.py
index b074f52dd1..8593e2d5b5 100644
--- a/vertexai/preview/rag/rag_data.py
+++ b/vertexai/preview/rag/rag_data.py
@@ -465,7 +465,7 @@ def upload_file(
         "metadata": (None, str(js_rag_file)),
         "file": open(path, "rb"),
     }
-    credentials, _ = auth.default()
+    credentials, _ = auth.default(scopes=['https://www.googleapis.com/auth/cloud-platform'])
     authorized_session = google_auth_requests.AuthorizedSession(credentials=credentials)
     try:
         response = authorized_session.post(