diff --git a/clang/include/clang/Basic/ABI.h b/clang/include/clang/Basic/ABI.h
index 5943b3f880e0..75e9faf4617e 100644
--- a/clang/include/clang/Basic/ABI.h
+++ b/clang/include/clang/Basic/ABI.h
@@ -17,6 +17,7 @@
 #define LLVM_CLANG_BASIC_ABI_H
 
 #include "llvm/Support/DataTypes.h"
+#include <cstring>
 
 namespace clang {