diff --git a/Lex/Preprocessor.cpp b/Lex/Preprocessor.cpp
index 25ddb03d48a782202ef88671533ea23521db99e5..b51222cefd3bdcb9c1dbe822f2f7463d3b9221d6 100644
--- a/Lex/Preprocessor.cpp
+++ b/Lex/Preprocessor.cpp
@@ -38,6 +38,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <iostream>
+#include <ctime>
 using namespace clang;
 
 //===----------------------------------------------------------------------===//