diff --git a/test/generic_category_test3.cpp b/test/generic_category_test3.cpp
index 5716059..5abc5f6 100644
--- a/test/generic_category_test3.cpp
+++ b/test/generic_category_test3.cpp
@@ -21,5 +21,10 @@ int main()
     BOOST_TEST( cat.default_error_condition( ENOENT ) == sys::error_condition( ENOENT, cat ) );
     BOOST_TEST( cat.default_error_condition( -1 ) == sys::error_condition( -1, cat ) );
 
+    // failed
+    BOOST_TEST( !cat.failed( 0 ) );
+    BOOST_TEST( cat.failed( ENOENT ) );
+    BOOST_TEST( cat.failed( -1 ) );
+
     return boost::report_errors();
 }
diff --git a/test/system_category_test3.cpp b/test/system_category_test3.cpp
index d03a305..3005639 100644
--- a/test/system_category_test3.cpp
+++ b/test/system_category_test3.cpp
@@ -30,5 +30,10 @@ int main()
 
 #endif
 
+    // failed
+    BOOST_TEST( !cat.failed( 0 ) );
+    BOOST_TEST( cat.failed( 5 ) );
+    BOOST_TEST( cat.failed( -1 ) );
+
     return boost::report_errors();
 }