diff --git a/docs/requirements.txt b/docs/requirements.txt
index 1560ebc5f9d74fbae773ac5bc45c5b42b044287a..90c6171099d9bb6e5ce32ac1164ba848c14426f4 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -2,3 +2,4 @@ sphinx==2.1.0
 mistune
 sphinx_rtd_theme
 paddlepaddle>=1.6
+zmq
diff --git a/paddle_fl/core/trainer/diffiehellman/diffiehellman.py b/paddle_fl/core/trainer/diffiehellman/diffiehellman.py
index 3d3e18a706a15865d9ef50c8bd3138645e0cff8c..364d01b82d560627555e031873c1a07993d41165 100644
--- a/paddle_fl/core/trainer/diffiehellman/diffiehellman.py
+++ b/paddle_fl/core/trainer/diffiehellman/diffiehellman.py
@@ -42,9 +42,9 @@ try:
     from ssl import RAND_bytes
     rng = RAND_bytes
 except(AttributeError, ImportError):
-    raise RNGError
-#python2
-#rng = os.urandom
+    #python2
+    rng = os.urandom
+    #raise RNGError
 
 class DiffieHellman:
     """
diff --git a/paddle_fl/core/trainer/fl_trainer.py b/paddle_fl/core/trainer/fl_trainer.py
index 7d162165d38faaaefe2c4b8f0eef5baf5ad5ed32..5e610e9e66bdaffa7d822813db169f252a039e6a 100755
--- a/paddle_fl/core/trainer/fl_trainer.py
+++ b/paddle_fl/core/trainer/fl_trainer.py
@@ -16,7 +16,7 @@ import logging
 from paddle_fl.core.scheduler.agent_master import FLWorkerAgent
 import numpy
 import hmac
-#from .diffiehellman.diffiehellman import DiffieHellman
+from .diffiehellman.diffiehellman import DiffieHellman
 
 class FLTrainerFactory(object):
     def __init__(self):