diff --git a/polymorphism/include/polymorphism/impl_with_interface.hpp b/polymorphism/include/polymorphism/impl_with_interface.hpp
index 8f64ced..7d513ac 100644
--- a/polymorphism/include/polymorphism/impl_with_interface.hpp
+++ b/polymorphism/include/polymorphism/impl_with_interface.hpp
@@ -21,6 +21,6 @@ class Impl
     }
 };
 
-} // namespace modern
+} // namespace classic
 
 #endif // IMPL_WITH_INTERFACE_HPP
\ No newline at end of file