diff --git a/libc/include/features.h b/libc/include/features.h
index 27dd823d..da5b2e29 100644
--- a/libc/include/features.h
+++ b/libc/include/features.h
@@ -22,8 +22,8 @@
 
 *******************************************************************************/
 
-#ifndef _FEATURES_H
-#define _FEATURES_H	1
+#ifndef INCLUDE_FEATURES_H
+#define INCLUDE_FEATURES_H 1
 
 #define __sortix_libc__ 1
 
@@ -43,9 +43,9 @@
 #define __PRAGMA_WARNING(msg) _Pragma(__STRINGIFY(GCC warning msg))
 
 /* C++ needs to know that types and declarations are C, not C++. */
-#ifdef	__cplusplus
-	#define __BEGIN_DECLS	extern "C" {
-	#define __END_DECLS		}
+#ifdef __cplusplus
+	#define __BEGIN_DECLS   extern "C" {
+	#define __END_DECLS     }
 #else
 	#define __BEGIN_DECLS
 	#define __END_DECLS