diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index da5b158..f858ce5 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Assembly/Parser.h"
 #include <cstring>
+#include <cstdlib>
 using namespace llvm;
 
 bool LLLexer::Error(LocTy ErrorLoc, const std::string &Msg) const {