diff --git a/llvm/lib/Transforms/Hello/Hello.cpp b/llvm/lib/Transforms/Hello/Hello.cpp
index b6262118efa9..36a60fa9d7ca 100644
--- a/llvm/lib/Transforms/Hello/Hello.cpp
+++ b/llvm/lib/Transforms/Hello/Hello.cpp
@@ -14,6 +14,7 @@
 
 #include "llvm/Pass.h"
 #include "llvm/Function.h"
+#include <iostream>
 using namespace llvm;
 
 namespace {