diff --git a/llvm/include/llvm/Support/system_error.h b/llvm/include/llvm/Support/system_error.h
index e5306ecfb35c..47759b99ecc5 100644
--- a/llvm/include/llvm/Support/system_error.h
+++ b/llvm/include/llvm/Support/system_error.h
@@ -1,4 +1,4 @@
-//===---------------------------- system_error ----------------------------===//
+//===---------------------------- system_error ------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //