diff --git a/include/field_reflection.hpp b/include/field_reflection.hpp
index d1b054f..da7ad1c 100644
--- a/include/field_reflection.hpp
+++ b/include/field_reflection.hpp
@@ -1,5 +1,5 @@
 /*===================================================*
-|  field-reflection version v0.2.0                   |
+|  field-reflection version v0.2.1                   |
 |  https://github.com/yosh-matsuda/field-reflection  |
 |                                                    |
 |  Copyright (c) 2024 Yoshiki Matsuda @yosh-matsuda  |
@@ -22,6 +22,11 @@ namespace field_reflection
 {
     namespace detail
     {
+
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wundefined-inline"
+#endif
         template <typename T, std::size_t = 0>
         struct any_lref
         {
@@ -78,6 +83,9 @@ namespace field_reflection
             requires std::is_base_of_v<U, T>
             constexpr operator U() const&& noexcept;  // NOLINT
         };
+#if defined(__GNUC__) || defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
 
         template <typename T, std::size_t ArgNum>
         concept constructible = []() {