diff --git a/build/Jamfile.v2 b/build/Jamfile.v2
index 8cc2ca8..b107a15 100644
--- a/build/Jamfile.v2
+++ b/build/Jamfile.v2
@@ -25,6 +25,7 @@ lib boost_mpi
     computation_tree.cpp
     content_oarchive.cpp
     environment.cpp
+    exception.cpp
     group.cpp
     mpi_datatype_cache.cpp
     mpi_datatype_oarchive.cpp
@@ -68,7 +69,7 @@ lib boost_mpi
         python/datatypes.cpp
         python/documentation.cpp
         python/py_environment.cpp
-        python/exception.cpp
+        python/py_exception.cpp
         python/module.cpp
         python/py_request.cpp
         python/skeleton_and_content.cpp
diff --git a/doc/mpi.qbk b/doc/mpi.qbk
index e92b7d3..20d1d4b 100644
--- a/doc/mpi.qbk
+++ b/doc/mpi.qbk
@@ -1571,7 +1571,7 @@ Boost.MPI translates MPI errors into exceptions, reported via the
   [[[@http://www.mpi-forum.org/docs/mpi-11-html/node148.html#Node148
   `MPI_Error_string`]] [used internally by Boost.MPI]]
   [[[@http://www.mpi-forum.org/docs/mpi-11-html/node149.html#Node149
-  `MPI_Error_class`]] [unsupported]]  
+  `MPI_Error_class`]] [[memberref boost::mpi::exception::error_class `exception::error_class`]]]
 ]
 
 The MPI timing facilities are exposed via the Boost.MPI [classref
diff --git a/include/boost/mpi/exception.hpp b/include/boost/mpi/exception.hpp
index cf25b67..4ba4d11 100644
--- a/include/boost/mpi/exception.hpp
+++ b/include/boost/mpi/exception.hpp
@@ -15,6 +15,7 @@
 
 #include <mpi.h>
 #include <exception>
+#include <string>
 #include <boost/config.hpp>
 #include <boost/throw_exception.hpp>
 
@@ -41,33 +42,47 @@ class exception : public std::exception
    *   @param result_code The result code returned from the MPI
    *   routine that aborted with an error.
    */
-  exception(const char* routine, int result_code)
-    : routine_(routine), result_code_(result_code) { }
+  exception(const char* routine, int result_code);
+
+  virtual ~exception() throw();
 
   /**
-   * A description of the error that occured. At present, this refers
-   * only to the name of the MPI routine that failed.
+   * A description of the error that occurred. 
    */
   virtual const char * what () const throw ()
   {
-    return routine_;
+    return this->message.c_str();
   }
 
   /** Retrieve the name of the MPI routine that reported the error. */
   const char* routine() const { return routine_; }
 
   /**
-   * Retrieve the result code returned from the MPI routine that
-   * reported the error.
+   * @brief Retrieve the result code returned from the MPI routine
+   * that reported the error.
    */
   int result_code() const { return result_code_; }
 
+  /**
+   * @brief Returns the MPI error class associated with the error that
+   * triggered this exception.
+   */
+  int error_class() const 
+  { 
+    int result;
+    MPI_Error_class(result_code_, &result);
+    return result;
+  }
+
  protected:
   /// The MPI routine that triggered the error
   const char* routine_;
 
   /// The failed result code reported by the MPI implementation.
   int result_code_;
+
+  /// The formatted error message
+  std::string message;
 };
 
 /**
diff --git a/src/exception.cpp b/src/exception.cpp
new file mode 100644
index 0000000..9cb4c25
--- /dev/null
+++ b/src/exception.cpp
@@ -0,0 +1,29 @@
+// Copyright (C) 2007 Trustees of Indiana University
+
+// Authors: Douglas Gregor
+//          Andrew Lumsdaine
+
+// Use, modification and distribution is subject to the Boost Software
+// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#include <boost/mpi/exception.hpp>
+
+namespace boost { namespace mpi {
+
+exception::exception(const char* routine, int result_code)
+  : routine_(routine), result_code_(result_code)
+{
+  // Query the MPI implementation for its reason for failure
+  char buffer[MPI_MAX_ERROR_STRING];
+  int len;
+  MPI_Error_string(result_code, buffer, &len);
+
+  // Construct the complete error message
+  message.append(routine_);
+  message.append(": ");
+  message.append(buffer, len);
+}
+
+exception::~exception() throw() { }
+
+} } // end namespace boost::mpi
diff --git a/src/python/Attic/exception.cpp b/src/python/py_exception.cpp
similarity index 100%
rename from src/python/Attic/exception.cpp
rename to src/python/py_exception.cpp