diff --git a/.travis.yml b/.travis.yml
index 41fc7f5..1fd3f02 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,7 @@
 sudo: false
 language: python
 python:
-    - "3.6"
+    - "3.7"
 notifications:
   email: junchen.feng@17zuoye.com
 install: "make" 
diff --git a/Pipfile b/Pipfile
index 32da63b..abdb3d0 100644
--- a/Pipfile
+++ b/Pipfile
@@ -22,3 +22,4 @@ tqdm = "*"
 cython = "*"
 pymongo = "*"
 python-decouple = "*"
+multiprocess = "*"
\ No newline at end of file
diff --git a/pyirt/solver/model.py b/pyirt/solver/model.py
index 1b96d86..4788dd9 100644
--- a/pyirt/solver/model.py
+++ b/pyirt/solver/model.py
@@ -19,7 +19,7 @@
 from ..algo import update_theta_distribution
 
 from datetime import datetime
-import multiprocessing as mp
+import multiprocess as mp
 from tqdm import tqdm
 
 
diff --git a/setup.py b/setup.py
index fe3565b..1973ac6 100644
--- a/setup.py
+++ b/setup.py
@@ -21,7 +21,8 @@
                       'cython',
                       'pymongo',
                       'tqdm',
-                      'python-decouple'],
+                      'python-decouple',
+                      'multiprocess'],
 
     package_data={'pyirt': ["*.pyx"]},