diff -ruN boost_1_54_0-boot/boost/asio/detail/impl/signal_set_service.ipp boost_1_54_0-patched/boost/asio/detail/impl/signal_set_service.ipp
--- boost_1_54_0-boot/boost/asio/detail/impl/signal_set_service.ipp	2013-05-27 05:36:39.000000000 -0700
+++ boost_1_54_0-patched/boost/asio/detail/impl/signal_set_service.ipp	2013-10-30 13:44:02.103770872 -0700
@@ -219,7 +219,7 @@
     int signal_number, boost::system::error_code& ec)
 {
   // Check that the signal number is valid.
-  if (signal_number < 0 || signal_number > max_signal_number)
+  if (signal_number < 0 || signal_number >= max_signal_number)
   {
     ec = boost::asio::error::invalid_argument;
     return ec;
@@ -293,7 +293,7 @@
     int signal_number, boost::system::error_code& ec)
 {
   // Check that the signal number is valid.
-  if (signal_number < 0 || signal_number > max_signal_number)
+  if (signal_number < 0 || signal_number >= max_signal_number)
   {
     ec = boost::asio::error::invalid_argument;
     return ec;