do not use reserved identifiers
diff --git a/libasn1fix/asn1fix_enum.h b/libasn1fix/asn1fix_enum.h
index 14c6fb5..7c2a9db 100644
--- a/libasn1fix/asn1fix_enum.h
+++ b/libasn1fix/asn1fix_enum.h
@@ -1,6 +1,6 @@
-#ifndef	_ASN1FIX_ENUM_H_
-#define	_ASN1FIX_ENUM_H_
+#ifndef	ASN1FIX_ENUM_H
+#define	ASN1FIX_ENUM_H
 
 int asn1f_fix_enum(arg_t *);	/* Enumeration ::= ENUMERATED { a(1), b(2) } */
 
-#endif	/* _ASN1FIX_ENUM_H_ */
+#endif	/* ASN1FIX_ENUM_H */