diff --git a/include/fmt/core.h b/include/fmt/core.h
index be0b6a880798..f194a4dc0df3 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -395,9 +395,9 @@ FMT_CONSTEXPR auto to_unsigned(Int value) ->
   return static_cast<typename std::make_unsigned<Int>::type>(value);
 }
 
-FMT_MSC_WARNING(suppress : 4566) constexpr unsigned char section[] = "\u00A7";
+FMT_CONSTEXPR inline auto is_utf8() -> bool {
+  FMT_MSC_WARNING(suppress : 4566) constexpr unsigned char section[] = "\u00A7";
 
-constexpr auto is_utf8() -> bool {
   // Avoid buggy sign extensions in MSVC's constant evaluation mode (#2297).
   using uchar = unsigned char;
   return FMT_UNICODE || (sizeof(section) == 3 && uchar(section[0]) == 0xC2 &&