diff --git a/include/lib/libc/stdarg.h b/include/lib/libc/stdarg.h
index 3c20788..e260b9b 100644
--- a/include/lib/libc/stdarg.h
+++ b/include/lib/libc/stdarg.h
@@ -3,9 +3,13 @@
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
+/*
+ * Portions copyright (c) 2018, ARM Limited and Contributors.
+ * All rights reserved.
+ */
 
-#ifndef _STDARG_H
-#define _STDARG_H
+#ifndef STDARG_H
+#define STDARG_H
 
 #define va_list __builtin_va_list
 #define va_start(ap, last) __builtin_va_start(ap, last)
@@ -13,4 +17,4 @@
 #define va_copy(to, from) __builtin_va_copy(to, from)
 #define va_arg(to, type) __builtin_va_arg(to, type)
 
-#endif
+#endif /* STDARG_H */