diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index bca127755..edf4a7fce 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,11 @@
+2015-04-22  Corinna Vinschen  <vinschen@redhat.com>
+
+	* libc/include/libgen.h (basename): Drop defining _BASENAME_DEFINED.
+	Always define macro basename.  Add comment to explain why.
+	* libc/include/string.h (basename): Check for basename instead of
+	_BASENAME_DEFINED.  Drop __GNUC__ branch, always use basename macro.
+	Change comment to explain why.  Add nonnull function attribute.
+
 2015-04-09  Nick Clifton  <nickc@redhat.com>
 
 	* libc/machine/rx/memchr.S: Add non-string insn using version.
diff --git a/newlib/libc/include/libgen.h b/newlib/libc/include/libgen.h
index 8360a22f9..de70b5b2f 100644
--- a/newlib/libc/include/libgen.h
+++ b/newlib/libc/include/libgen.h
@@ -12,8 +12,20 @@
 extern "C" {
 #endif
 
+/* There are two common basename variants.  If you do NOT #include <libgen.h>
+   and you do
+
+     #define _GNU_SOURCE
+     #include <string.h>
+
+   you get the GNU version.  Otherwise you get the POSIX versionfor which you
+   should #include <libgen.h>i for the function prototype.  POSIX requires that
+   #undef basename will still let you invoke the underlying function.  However,
+   this also implies that the POSIX version is used in this case.  That's made
+   sure here. */
+#undef basename
+#define basename basename
 char      *_EXFUN(basename,     (char *));
-#define _BASENAME_DEFINED
 char      *_EXFUN(dirname,     (char *));
 
 #ifdef __cplusplus
diff --git a/newlib/libc/include/string.h b/newlib/libc/include/string.h
index 9e11e5c51..92e08aebc 100644
--- a/newlib/libc/include/string.h
+++ b/newlib/libc/include/string.h
@@ -163,18 +163,20 @@ int	_EXFUN(strtosigno, (const char *__name));
 			 (char *) memcpy (__out, __in, __len-1);}))
 #endif /* _GNU_SOURCE && __GNUC__ */
 
-/* There are two common basename variants.  If you #include <libgen.h>
-   first, you get the POSIX version; otherwise you get the GNU version.
-   POSIX requires that #undef basename will still let you
-   invoke the underlying function, but that requires gcc support.  */
-#if __GNU_VISIBLE && !defined(_BASENAME_DEFINED)
-# ifdef __GNUC__
-char	*_EXFUN(basename,(const char *))
-             __asm__ (__ASMNAME ("__gnu_basename")) __nonnull(1);
-# else
-char	*_EXFUN(__gnu_basename,(const char *));
+/* There are two common basename variants.  If you do NOT #include <libgen.h>
+   and you do
+
+     #define _GNU_SOURCE
+     #include <string.h>
+
+   you get the GNU version.  Otherwise you get the POSIX versionfor which you
+   should #include <libgen.h>i for the function prototype.  POSIX requires that
+   #undef basename will still let you invoke the underlying function.  However,
+   this also implies that the POSIX version is used in this case.  That's made
+   sure here. */
+#if __GNU_VISIBLE && !defined(basename)
+char	*_EXFUN(__nonnull (1) __gnu_basename,(const char *));
 # define basename __gnu_basename
-# endif
 #endif
 
 #include <sys/string.h>