diff --git a/superset/db_engine_specs/hive.py b/superset/db_engine_specs/hive.py
index 484e867ab0a88..344d1f7ae9334 100644
--- a/superset/db_engine_specs/hive.py
+++ b/superset/db_engine_specs/hive.py
@@ -65,6 +65,7 @@ def upload_to_s3(filename: str, upload_prefix: str, table: Table) -> str:
 
     # pylint: disable=import-outside-toplevel
     import boto3
+    from boto3.s3.transfer import TransferConfig
 
     bucket_path = current_app.config["CSV_TO_HIVE_UPLOAD_S3_BUCKET"]
 
@@ -80,6 +81,7 @@ def upload_to_s3(filename: str, upload_prefix: str, table: Table) -> str:
         filename,
         bucket_path,
         os.path.join(upload_prefix, table.table, os.path.basename(filename)),
+        Config=TransferConfig(use_threads=False),  # Threading is broken in Python 3.9.
     )
     return location