diff --git a/paddle/gserver/gradientmachines/NeuralNetwork.cpp b/paddle/gserver/gradientmachines/NeuralNetwork.cpp
index f9da812027dc3a5af026f44a608a14a5b1de2618..903922204343ec49a1696eb35b06c127310b432d 100644
--- a/paddle/gserver/gradientmachines/NeuralNetwork.cpp
+++ b/paddle/gserver/gradientmachines/NeuralNetwork.cpp
@@ -384,17 +384,10 @@ void NeuralNetwork::setOutputGrad(const std::vector<Argument>& args) {
   }
 }
 
-// extern NeuralNetwork* newCustomNeuralNetwork(
-//    const std::string& name, NeuralNetwork* network) __attribute__((weak));
-
 NeuralNetwork* NeuralNetwork::newNeuralNetwork(
     const std::string& name,
     NeuralNetwork* rootNetwork) {
-//  if (newCustomNeuralNetwork) {
-//    return newCustomNeuralNetwork(name, rootNetwork);
-//  } else {
     return new NeuralNetwork(name, rootNetwork);
-//  }
 }
 
 }  // namespace paddle