diff --git a/demo/mnist/api_train.py b/demo/mnist/api_train.py
index b061cfb2b8f1faa7979093af19288475b99c57ff..59043ce6c42085fe1988ceba8358b97cb01f74c7 100644
--- a/demo/mnist/api_train.py
+++ b/demo/mnist/api_train.py
@@ -35,6 +35,8 @@ def main():
     for _ in xrange(100):
         updater.startPass()
 
+        updater.finishPass()
+
     m.finish()
 
 
diff --git a/paddle/api/ParameterUpdater.cpp b/paddle/api/ParameterUpdater.cpp
index 3b626c05071393740d198d9785879ea35d89647d..4edec78b4a3d42f226a155663a03f84b1840e03b 100644
--- a/paddle/api/ParameterUpdater.cpp
+++ b/paddle/api/ParameterUpdater.cpp
@@ -34,4 +34,4 @@ void ParameterUpdater::init(const GradientMachine &gm) {
 
 void ParameterUpdater::startPass() { m->updater->startPass(); }
 
-void ParameterUpdater::finishPass() {}
+void ParameterUpdater::finishPass() { m->updater->finishPass(); }