diff --git a/test/variant_valueless.cpp b/test/variant_valueless.cpp
index 34b90af..6a13086 100644
--- a/test/variant_valueless.cpp
+++ b/test/variant_valueless.cpp
@@ -230,8 +230,18 @@ int main()
         }
         catch( std::exception const& )
         {
-            // all trivially destructible and move-assignable, no change
-            BOOST_TEST_EQ( v.index(), 0 );
+            // X3 is not v2d::trivially_move_assignable on libstdc++ 4.x
+
+            if( v2d::is_trivially_move_assignable<X3>::value )
+            {
+                // all trivially destructible and move-assignable, no change
+                BOOST_TEST_EQ( v.index(), 0 );
+            }
+            else
+            {
+                // basic guarantee; X1 is nothrow default-constructible
+                BOOST_TEST_EQ( v.index(), 1 );
+            }
         }
     }
 
@@ -247,8 +257,18 @@ int main()
         }
         catch( std::exception const& )
         {
-            // all trivially destructible and move-assignable, no change
-            BOOST_TEST_EQ( v.index(), 0 );
+            // X3 is not v2d::trivially_move_assignable on libstdc++ 4.x
+
+            if( v2d::is_trivially_move_assignable<X3>::value )
+            {
+                // all trivially destructible and move-assignable, no change
+                BOOST_TEST_EQ( v.index(), 0 );
+            }
+            else
+            {
+                // basic guarantee; monostate
+                BOOST_TEST_EQ( v.index(), 2 );
+            }
         }
     }