diff --git a/llvm/tools/llvm-diff/DiffLog.h b/llvm/tools/llvm-diff/DiffLog.h
index 43e318a..8eb53ff 100644
--- a/llvm/tools/llvm-diff/DiffLog.h
+++ b/llvm/tools/llvm-diff/DiffLog.h
@@ -11,8 +11,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LLVM_DIFFLOG_H_
-#define _LLVM_DIFFLOG_H_
+#ifndef LLVM_TOOLS_LLVM_DIFF_DIFFLOG_H
+#define LLVM_TOOLS_LLVM_DIFF_DIFFLOG_H
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"