diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -137,24 +137,10 @@
 #define	__P(protos)	()		/* traditional C preprocessor */
 #define	__CONCAT(x,y)	x/**/y
 #define	__STRING(x)	"x"
-
 #if !defined(__CC_SUPPORTS___INLINE)
+/* Just delete these in a K&R environment */
 #define	__inline
 #define	__volatile
-/*
- * In non-ANSI C environments, new programs will want ANSI-only C keywords
- * deleted from the program and old programs will want them left alone.
- * When using a compiler other than gcc, programs using the ANSI C keywords
- * const, inline etc. as normal identifiers should define -DNO_ANSI_KEYWORDS.
- * When using "gcc -traditional", we assume that this is the intent; if
- * __GNUC__ is defined but __STDC__ is not, we leave the new keywords alone.
- */
-#ifndef	NO_ANSI_KEYWORDS
-#define	const				/* delete ANSI C keywords */
-#define	inline
-#define	signed
-#define	volatile
-#endif	/* !NO_ANSI_KEYWORDS */
 #endif	/* !__CC_SUPPORTS___INLINE */
 #endif	/* !(__STDC__ || __cplusplus) */