diff --git a/include/nlohmann/detail/json_custom_base_class.hpp b/include/nlohmann/detail/json_custom_base_class.hpp
index f749c25e2..2eb108b16 100644
--- a/include/nlohmann/detail/json_custom_base_class.hpp
+++ b/include/nlohmann/detail/json_custom_base_class.hpp
@@ -26,4 +26,4 @@ using json_base_class = typename std::conditional <
                         >::type;
 
 }  // namespace detail
-}  // namespace nlohmann
+NLOHMANN_JSON_NAMESPACE_END