diff --git a/compiler-rt/lib/xray/xray_emulate_tsc.h b/compiler-rt/lib/xray/xray_emulate_tsc.h
index 14a7993bc552..ece672c82bd9 100644
--- a/compiler-rt/lib/xray/xray_emulate_tsc.h
+++ b/compiler-rt/lib/xray/xray_emulate_tsc.h
@@ -1,8 +1,22 @@
-#pragma once
-#include <time.h>
+//===-- xray_emulate_tsc.h --------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of XRay, a dynamic runtime instrumentation system.
+//
+//===----------------------------------------------------------------------===//
+#ifndef XRAY_EMULATE_TSC_H
+#define XRAY_EMULATE_TSC_H
 
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "xray_defs.h"
+#include <cstdint>
+#include <time.h>
 
 namespace __xray {
 
@@ -19,5 +33,6 @@ ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
   CPU = 0;
   return TS.tv_sec * NanosecondsPerSecond + TS.tv_nsec;
 }
-
 }
+
+#endif // XRAY_EMULATE_TSC_H
diff --git a/compiler-rt/lib/xray/xray_x86_64.h b/compiler-rt/lib/xray/xray_x86_64.h
index c34e02ce79c2..52d2dea8f0d9 100644
--- a/compiler-rt/lib/xray/xray_x86_64.h
+++ b/compiler-rt/lib/xray/xray_x86_64.h
@@ -1,4 +1,19 @@
-#pragma once
+//===-- xray_x86_64.h -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of XRay, a dynamic runtime instrumentation system.
+//
+//===----------------------------------------------------------------------===//
+#ifndef XRAY_X86_64_H
+#define XRAY_X86_64_H
+
+#include <cstdint>
 #include <x86intrin.h>
 
 #include "sanitizer_common/sanitizer_internal_defs.h"
@@ -12,5 +27,6 @@ ALWAYS_INLINE uint64_t readTSC(uint8_t &CPU) XRAY_NEVER_INSTRUMENT {
   CPU = LongCPU;
   return TSC;
 }
-
 }
+
+#endif // XRAY_X86_64_H