diff --git a/test/expected.t.cpp b/test/expected.t.cpp
index 5163b0e..6228a77 100644
--- a/test/expected.t.cpp
+++ b/test/expected.t.cpp
@@ -276,26 +276,35 @@ CASE( "unexpected_type: Allows to move-construct from unexpected_type, non-expli
 
 CASE( "unexpected_type: Allows to copy-assign from unexpected_type, default" )
 {
+#if !nsel_USES_STD_EXPECTED
     unexpected_type<int> a{ 7   };
     unexpected_type<int> b{ 0 };
 
     b = a;
 
     EXPECT( b.error() == 7 );
+#else
+    EXPECT( !!"no assignment for std::unexpected (C++23)." );
+#endif
 }
 
 CASE( "unexpected_type: Allows to move-assign from unexpected_type, default" )
 {
+#if !nsel_USES_STD_EXPECTED
     unexpected_type<int> a{ 7 };
     unexpected_type<int> b{ 0 };
 
     b = std::move( a );
 
     EXPECT( b.error() == 7 );
+#else
+    EXPECT( !!"no assignment for std::unexpected (C++23)." );
+#endif
 }
 
 CASE( "unexpected_type: Allows to copy-assign from unexpected_type, converting" )
 {
+#if !nsel_USES_STD_EXPECTED
     unexpected_type<int> u{ 7 };
     unexpected_type<Explicit> ue{ 0 };
     unexpected_type<Implicit> ui{ 0 };
@@ -305,6 +314,9 @@ CASE( "unexpected_type: Allows to copy-assign from unexpected_type, converting"
 
     EXPECT( ue.error() == Explicit{7} );
     EXPECT( ui.error() == Implicit{7} );
+#else
+    EXPECT( !!"no assignment for std::unexpected (C++23)." );
+#endif
 }
 
 CASE( "unexpected_type: Allows to move-assign from unexpected, converting" )