diff --git a/make_data_files.py b/make_data_files.py
index b22ff38..bea6465 100644
--- a/make_data_files.py
+++ b/make_data_files.py
@@ -56,8 +56,8 @@ def write_to_bin(article_path, abstract_path, out_file, vocab_counter = None):
             abstract = next(abstract_itr).strip()
 
             tf_example = example_pb2.Example()
-            tf_example.features.feature['article'].bytes_list.value.extend([article])
-            tf_example.features.feature['abstract'].bytes_list.value.extend([abstract])
+            tf_example.features.feature['article'].bytes_list.value.extend([bytes(article, 'utf-8')])
+            tf_example.features.feature['abstract'].bytes_list.value.extend([bytes(abstract, 'utf-8')])
             tf_example_str = tf_example.SerializeToString()
             str_len = len(tf_example_str)
             writer.write(struct.pack('q', str_len))