diff --git a/docs/cpp/header-files-cpp.md b/docs/cpp/header-files-cpp.md
index 0c35f41c73e..6876369aa02 100644
--- a/docs/cpp/header-files-cpp.md
+++ b/docs/cpp/header-files-cpp.md
@@ -111,6 +111,7 @@ Use of the **using** directive will not necessarily cause an error, but can pote
 The following example shows the various kinds of declarations and definitions that are allowed in a header file:
 
 ```cpp
+// sample.h
 #pragma once
 #include <vector> // #include directive
 #include <string>