#elif defined( SYS_DARWIN )
# define HB_LOW_PRIORITY 0
# define HB_NORMAL_PRIORITY 31
-#elif defined( SYS_LINUX ) || defined( SYS_FREEBSD )
+#elif defined( SYS_LINUX ) || defined( SYS_FREEBSD ) || defined ( SYS_SunOS )
# define HB_LOW_PRIORITY 0
# define HB_NORMAL_PRIORITY 0
#elif defined( SYS_CYGWIN )