-#ifndef _xstrtoul_h_
-#define _xstrtoul_h_ 1
+#ifndef XSTRTOUL_H_
+# define XSTRTOUL_H_ 1
-#define STRING_TO_UNSIGNED 1
-#include "xstrtol.h"
+# define STRING_TO_UNSIGNED 1
+# include "xstrtol.h"
-#endif /* _xstrtoul_h_ */
+#endif /* not XSTRTOUL_H_ */