diff --git a/sumstats_service/resources/globus.py b/sumstats_service/resources/globus.py
index a7c4f92..5cdfde5 100644
--- a/sumstats_service/resources/globus.py
+++ b/sumstats_service/resources/globus.py
@@ -6,7 +6,7 @@
 import pathlib
 from sumstats_service import config
 import globus_sdk
-from globus_sdk import (NativeAppAuthClient, TransferClient, AccessTokenAuthorizer,
+from globus_sdk import (NativeAppAuthClient, TransferClient, AccessTokenAuthorizer, RefreshTokenAuthorizer,
                         ClientCredentialsAuthorizer, ConfidentialAppAuthClient, DeleteData,
                         GCSClient, scopes, GuestCollectionDocument, TransferAPIError, GlobusAPIError)
 from sumstats_service.resources.globus_utils import is_remote_session
@@ -54,9 +54,14 @@ def init_transfer_client() -> TransferClient:
         # if we need to get tokens, start the Native App authentication process
         tokens = do_native_app_authentication(config.TRANSFER_CLIENT_ID, config.REDIRECT_URI, config.SCOPES)
         save_tokens_to_db(tokens)
-    transfer_access_token = tokens['transfer.api.globus.org']['access_token']
-    transfer_authorizer = AccessTokenAuthorizer(transfer_access_token)
-    transfer_client = TransferClient(authorizer=transfer_authorizer)
+    transfer_tokens = tokens.get('transfer.api.globus.org')
+    native_app_client = NativeAppAuthClient(client_id=config.TRANSFER_CLIENT_ID)
+    authorizer = RefreshTokenAuthorizer(transfer_tokens['refresh_token'],
+                                        native_app_client,
+                                        access_token=transfer_tokens['access_token'],
+                                        expires_at=transfer_tokens['expires_at_seconds'],
+                                        on_refresh=save_tokens_to_db(tokens))
+    transfer_client = TransferClient(authorizer=authorizer)
     transfer_client.endpoint_autoactivate(config.MAPPED_COLLECTION_ID)
     return transfer_client
 
@@ -230,14 +235,6 @@ def save_tokens_to_db(tokens) -> None:
         globus_db_collection.insert(tokens, check_keys=False)
 
 
-def update_tokens_file_on_refresh(token_response):
-    """
-    Callback function passed into the RefreshTokenAuthorizer.
-    Will be invoked any time a new access token is fetched.
-    """
-    save_tokens_to_db(token_response.by_resource_server)
-
-
 def save_requirements_to_db(requirements):
     mongo_client = MongoClient(config.MONGO_URI, username=config.MONGO_USER, password=config.MONGO_PASSWORD)
     globus_db = mongo_client[config.MONGO_DB] # 'globus-tokens'