diff --git a/tools/program.py b/tools/program.py
index 30e9d737..3c71065a 100755
--- a/tools/program.py
+++ b/tools/program.py
@@ -114,7 +114,10 @@ def merge_config(config):
                 global_config[key] = value
         else:
             sub_keys = key.split('.')
-            assert (sub_keys[0] in global_config), "the sub_keys can only be one of global_config: {}, but get: {}, please check your running command".format(global_config.keys(), sub_keys[0])
+            assert (
+                sub_keys[0] in global_config
+            ), "the sub_keys can only be one of global_config: {}, but get: {}, please check your running command".format(
+                global_config.keys(), sub_keys[0])
             cur = global_config[sub_keys[0]]
             for idx, sub_key in enumerate(sub_keys[1:]):
                 assert (sub_key in cur)
@@ -177,7 +180,6 @@ def build(config, main_prog, startup_prog, mode):
                 optimizer.minimize(opt_loss)
                 opt_loss_name = opt_loss.name
                 global_lr = optimizer._global_learning_rate()
-                global_lr.persistable = True
                 fetch_name_list.insert(0, "lr")
                 fetch_varname_list.insert(0, global_lr.name)
     return (dataloader, fetch_name_list, fetch_varname_list, opt_loss_name)