Index: git/libc/sysdeps/linux/common/bits/mathcalls.h
===================================================================
--- git.orig/libc/sysdeps/linux/common/bits/mathcalls.h	2010-08-05 11:28:00.633339104 +0200
+++ git/libc/sysdeps/linux/common/bits/mathcalls.h	2010-08-05 11:38:03.545778271 +0200
@@ -235,15 +235,14 @@
 __END_NAMESPACE_C99
 #endif
 
-
-/* Return nonzero if VALUE is not a number.  */
-/* DELETE? __MATHDECL_PRIV adds another "__": so this is "____isnan"???! */
-/*__MATHDECL_PRIV (int,__isnan,, (_Mdouble_ __value), (__const__))*/
-
-#if defined __USE_MISC || defined __USE_XOPEN
+#if defined __USE_MISC || defined __USE_XOPEN || defined __USE_ISOC99
 /* Return nonzero if VALUE is not a number.  */
+__BEGIN_NAMESPACE_C99
 __MATHDECL_PRIV (int,isnan,, (_Mdouble_ __value), (__const__))
+__END_NAMESPACE_C99
+#endif
 
+#if defined __USE_MISC || defined __USE_XOPEN
 # ifdef __DO_XSI_MATH__
 /* Bessel functions.  */
 __MATHCALL (j0,, (_Mdouble_))