diff --git a/lpc_nuvoton.hpp b/lpc_nuvoton.hpp
index bf53e29..b72a673 100644
--- a/lpc_nuvoton.hpp
+++ b/lpc_nuvoton.hpp
@@ -29,6 +29,8 @@
         regionAddress(regionAddress),
         sys(sys){};
 
+    void close() override;
+
     std::pair<std::uint32_t, std::uint32_t>
         mapWindow(std::uint32_t address, std::uint32_t length) override;