diff --git a/include/llvm/CodeGen/PostRAHazardRecognizer.h b/include/llvm/CodeGen/PostRAHazardRecognizer.h
index 3f600f587d3..24d73cb7860 100644
--- a/include/llvm/CodeGen/PostRAHazardRecognizer.h
+++ b/include/llvm/CodeGen/PostRAHazardRecognizer.h
@@ -20,6 +20,7 @@
 #include "llvm/System/DataTypes.h"
 
 #include <cassert>
+#include <cstring>
 #include <string>
 
 namespace llvm {