diff --git a/c++2.0/c++11/nullptr.cpp b/c++2.0/c++11/nullptr.cpp
index a4a7822..5e36c24 100644
--- a/c++2.0/c++11/nullptr.cpp
+++ b/c++2.0/c++11/nullptr.cpp
@@ -2,7 +2,7 @@
 // Created by light on 19-11-2.
 //
 
-#include <iostream>
+#include <bits/stdc++.h>
 using namespace std;
 
 void f(int i) {