diff --git a/setup.py b/setup.py
index 94f58130c..b17656b5b 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@
 
 setup(
     name='tensor2tensor',
-    version='1.5.0',
+    version='1.5.1',
     description='Tensor2Tensor',
     author='Google Inc.',
     author_email='no-reply@google.com',
diff --git a/tensor2tensor/bin/t2t_trainer.py b/tensor2tensor/bin/t2t_trainer.py
index b2545a159..af7cb5077 100644
--- a/tensor2tensor/bin/t2t_trainer.py
+++ b/tensor2tensor/bin/t2t_trainer.py
@@ -274,7 +274,9 @@ def save_metadata(hparams):
   # Save hparams as hparams.json
   hparams_fname = os.path.join(output_dir, "hparams.json")
   with tf.gfile.Open(hparams_fname, "w") as f:
-    f.write(hparams.to_json(indent=0, sort_keys=True))
+    # TODO(lukaszkaiser): use the first line once we require TF 1.5+.
+    # f.write(hparams.to_json(indent=0, sort_keys=True))
+    f.write(hparams.to_json())
 
 
 def execute_schedule(exp):