diff --git a/misc/sys/cdefs.h b/misc/sys/cdefs.h
index f74671086e..3e874282df 100644
--- a/misc/sys/cdefs.h
+++ b/misc/sys/cdefs.h
@@ -606,14 +606,14 @@
 # define __attribute_artificial__ /* Ignore */
 #endif
 
-/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
-   inline semantics, unless -fgnu89-inline is used.  Using __GNUC_STDC_INLINE__
-   or __GNUC_GNU_INLINE is not a good enough check for gcc because gcc versions
+/* GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99 inline
+   semantics, unless -fgnu89-inline is used.  Using __GNUC_STDC_INLINE__ or
+   __GNUC_GNU_INLINE__ is not a good enough check for gcc because gcc versions
    older than 4.3 may define these macros and still not guarantee GNU inlining
    semantics.
 
    clang++ identifies itself as gcc-4.2, but has support for GNU inlining
-   semantics, that can be checked for by using the __GNUC_STDC_INLINE_ and
+   semantics, that can be checked for by using the __GNUC_STDC_INLINE__ and
    __GNUC_GNU_INLINE__ macro definitions.  */
 #if (!defined __cplusplus || __GNUC_PREREQ (4,3) \
      || (defined __clang__ && (defined __GNUC_STDC_INLINE__ \