diff --git a/asio/README b/asio/README
index 2e26369..6ea1a72 100644
--- a/asio/README
+++ b/asio/README
@@ -1,4 +1,4 @@
-asio version 1.8.0
-Released Wednesday, 23 May 2012.
+asio version 1.8.1
+Released Tuesday, 10 July 2012.
 
 See doc/index.html for API documentation and a tutorial.
diff --git a/asio/configure.ac b/asio/configure.ac
index d2e5208..703108c 100644
--- a/asio/configure.ac
+++ b/asio/configure.ac
@@ -1,4 +1,4 @@
-AC_INIT(asio, [1.8.0])
+AC_INIT(asio, [1.8.1])
 AC_CONFIG_SRCDIR(include/asio.hpp)
 AM_MAINTAINER_MODE
 AM_INIT_AUTOMAKE([tar-ustar])
diff --git a/asio/include/asio/version.hpp b/asio/include/asio/version.hpp
index 473551c..d86de93 100644
--- a/asio/include/asio/version.hpp
+++ b/asio/include/asio/version.hpp
@@ -18,6 +18,6 @@
 // ASIO_VERSION % 100 is the sub-minor version
 // ASIO_VERSION / 100 % 1000 is the minor version
 // ASIO_VERSION / 100000 is the major version
-#define ASIO_VERSION 100800 // 1.8.0
+#define ASIO_VERSION 100801 // 1.8.1
 
 #endif // ASIO_VERSION_HPP