diff --git a/src/tools.h b/src/tools.h
index e5d55409..3f809f4d 100644
--- a/src/tools.h
+++ b/src/tools.h
@@ -96,4 +96,18 @@ int64_t OTSYS_TIME();
 
 SpellGroup_t stringToSpellGroup(const std::string& value);
 
-#endif // FS_TOOLS_H
\ No newline at end of file
+namespace tfs {
+
+#if __has_cpp_attribute(__cpp_lib_to_underlying)
+
+inline constexpr auto to_underlying(auto e) noexcept { return std::to_underlying(e); }
+
+#else
+
+inline constexpr auto to_underlying(auto e) noexcept { return static_cast<std::underlying_type_t<decltype(e)>>(e); }
+
+#endif
+
+} // namespace tfs
+
+#endif // FS_TOOLS_H