diff --git a/include/boost/system/system_error.hpp b/include/boost/system/system_error.hpp
index fcc4f27..7b20cd9 100644
--- a/include/boost/system/system_error.hpp
+++ b/include/boost/system/system_error.hpp
@@ -35,17 +35,7 @@ private:
             r += ": ";
         }
 
-        r += ec.message();
-
-        if( ec.has_location() )
-        {
-            r += " [";
-            r += ec.to_string();
-            r += " at ";
-            r += ec.location().to_string();
-            r += "]";
-        }
-
+        r += ec.what();
         return r;
     }
 
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 902feff..bab504b 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -108,6 +108,7 @@ boost_test(TYPE run SOURCES std_interop_test10.cpp)
 
 boost_test(TYPE run SOURCES ec_location_test2.cpp)
 boost_test(TYPE run SOURCES ec_what_test.cpp)
+boost_test(TYPE run SOURCES system_error_test3.cpp)
 
 # result
 
diff --git a/test/Jamfile.v2 b/test/Jamfile.v2
index 75f6684..cde8abd 100644
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -130,6 +130,7 @@ run std_interop_test10.cpp ;
 
 run ec_location_test2.cpp ;
 run ec_what_test.cpp ;
+run system_error_test3.cpp ;
 
 # result
 
diff --git a/test/quick.cpp b/test/quick.cpp
index 58c7d76..77e21d1 100644
--- a/test/quick.cpp
+++ b/test/quick.cpp
@@ -37,7 +37,7 @@ int main()
     boost::system::system_error x( bc, "prefix" );
 
     BOOST_TEST_EQ( x.code(), bc );
-    BOOST_TEST_EQ( std::string( x.what() ), "prefix: " + bc.message() );
+    BOOST_TEST_EQ( std::string( x.what() ), "prefix: " + bc.what() );
 
     return boost::report_errors();
 }
diff --git a/test/system_error_test.cpp b/test/system_error_test.cpp
index d8e39e7..97fc677 100644
--- a/test/system_error_test.cpp
+++ b/test/system_error_test.cpp
@@ -81,27 +81,25 @@ int main( int, char *[] )
   system_error c6_0( 0, system_category(), "c6_0" ); 
   system_error c6_1( 1, system_category(), "c6_1" );
 
-  TEST( c1_0, 0, "The operation completed successfully" );
-  TEST( c1_1, 1, "Incorrect function" );
-  TEST( c1_2u, 2, "The system cannot find the file specified" );
+  TEST( c1_0, 0, "The operation completed successfully [system:0]" );
+  TEST( c1_1, 1, "Incorrect function [system:1]" );
+  TEST( c1_2u, 2, "The system cannot find the file specified [system:2]" );
 
-  TEST( c2_0, 0, "c2_0: The operation completed successfully" );
-  TEST( c2_1, 1, "c2_1: Incorrect function" );
+  TEST( c2_0, 0, "c2_0: The operation completed successfully [system:0]" );
+  TEST( c2_1, 1, "c2_1: Incorrect function [system:1]" );
 
-  TEST( c3_0, 0, "c3_0: The operation completed successfully" );
-  TEST( c3_1, 1, "c3_1: Incorrect function" );
+  TEST( c3_0, 0, "c3_0: The operation completed successfully [system:0]" );
+  TEST( c3_1, 1, "c3_1: Incorrect function [system:1]" );
 
-  TEST( c4_0, 0, "The operation completed successfully" );
-  TEST( c4_1, 1, "Incorrect function" );
-  TEST( c4_2u, 2, "The system cannot find the file specified" );
+  TEST( c4_0, 0, "The operation completed successfully [system:0]" );
+  TEST( c4_1, 1, "Incorrect function [system:1]" );
+  TEST( c4_2u, 2, "The system cannot find the file specified [system:2]" );
 
-  TEST( c5_0, 0, "c5_0: The operation completed successfully" );
-  TEST( c5_1, 1, "c5_1: Incorrect function" );
+  TEST( c5_0, 0, "c5_0: The operation completed successfully [system:0]" );
+  TEST( c5_1, 1, "c5_1: Incorrect function [system:1]" );
 
-  TEST( c6_0, 0, "c6_0: The operation completed successfully" );
-  TEST( c6_1, 1, "c6_1: Incorrect function" );
+  TEST( c6_0, 0, "c6_0: The operation completed successfully [system:0]" );
+  TEST( c6_1, 1, "c6_1: Incorrect function [system:1]" );
 
   return ::boost::report_errors();
 }
-
-
diff --git a/test/system_error_test3.cpp b/test/system_error_test3.cpp
new file mode 100644
index 0000000..e5b2da5
--- /dev/null
+++ b/test/system_error_test3.cpp
@@ -0,0 +1,42 @@
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/system_error.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+namespace sys = boost::system;
+
+int main()
+{
+    {
+        sys::error_code ec( 5, sys::generic_category() );
+        sys::system_error x1( ec );
+
+		BOOST_TEST_EQ( std::string( x1.what() ), ec.what() );
+    }
+
+    {
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        sys::error_code ec( 5, sys::system_category(), &loc );
+        sys::system_error x1( ec, "prefix" );
+
+        BOOST_TEST_EQ( std::string( x1.what() ), "prefix: " + ec.what() );
+    }
+
+    {
+        sys::system_error x1( 5, sys::generic_category() );
+
+        BOOST_TEST_EQ( std::string( x1.what() ), sys::error_code( 5, sys::generic_category() ).what() );
+    }
+
+    {
+        sys::system_error x1( 5, sys::system_category(), "prefix" );
+
+        BOOST_TEST_EQ( std::string( x1.what() ), "prefix: " + sys::error_code( 5, sys::system_category() ).what() );
+    }
+
+    return boost::report_errors();
+}