diff -Naruw geos-3.4.2.orig/include/geos/platform.h.in geos-3.4.2/include/geos/platform.h.in
--- geos-3.4.2.orig/include/geos/platform.h.in	2013-08-25 15:10:32.000000000 +0000
+++ geos-3.4.2/include/geos/platform.h.in	2013-10-20 23:45:29.891690795 +0000
@@ -98,8 +98,9 @@
    // It does leave a version in std.
 #  define ISNAN(x) (std::isnan(x))
 # elif (defined(__sun) || defined(__sun__)) && defined(__SUNPRO_CC)
+#  define _XOPEN_SOURCE 600 //force iso/math_c99
 #  include <math.h>
-#  define ISNAN(x) (::isnan(x))
+#  define ISNAN(x) (std::isnan(x))
 # endif
 #endif