diff --git a/system_tests/bigquery.py b/system_tests/bigquery.py
index a1972eb4a2e9..46bc6050fa13 100644
--- a/system_tests/bigquery.py
+++ b/system_tests/bigquery.py
@@ -263,15 +263,16 @@ def test_load_table_from_storage_then_dump_table(self):
         self.to_delete.append(bucket)
 
         blob = bucket.blob(BLOB_NAME)
-        self.to_delete.insert(0, blob)
 
-        with tempfile.TemporaryFile() as csv_file:
+        with tempfile.TemporaryFile(mode='w+') as csv_file:
             writer = csv.writer(csv_file)
             writer.writerow(('Full Name', 'Age'))
             writer.writerows(ROWS)
             blob.upload_from_file(
                 csv_file, rewind=True, content_type='text/csv')
 
+        self.to_delete.insert(0, blob)
+
         dataset = CLIENT.dataset(DATASET_NAME)
         dataset.create()
         self.to_delete.append(dataset)