diff --git a/README.md b/README.md
index 067776df16a7f420987e44302d85ff98c14289ee..1ef15c33dc71be53cae17f55a6077b90a51485a1 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ git clone https://github.com/PaddlePaddle/PALM.git
 - Python >= 2.7
 - cuda >= 9.0
 - cudnn >= 7.0
-- PaddlePaddle >= 1.5.0 (请参考[安装指南](http://www.paddlepaddle.org/#quick-start)进行安装)
+- PaddlePaddle >= 1.6 (请参考[安装指南](http://www.paddlepaddle.org/#quick-start)进行安装)
 
 ## 目录结构
 
diff --git a/backbone/utils/transformer.py b/backbone/utils/transformer.py
index edbda1ced9e7045edd555eabccdc5cb0befa6194..a76835a628559e33905836e49fd9cc2ecf052af5 100644
--- a/backbone/utils/transformer.py
+++ b/backbone/utils/transformer.py
@@ -18,6 +18,7 @@ from __future__ import division
 from __future__ import print_function
 
 from functools import partial
+from functools import reduce
 import numpy as np
 
 import paddle.fluid as fluid