diff --git a/include/fast_float/float_common.h b/include/fast_float/float_common.h
index 60c28c7..19027cd 100644
--- a/include/fast_float/float_common.h
+++ b/include/fast_float/float_common.h
@@ -257,6 +257,7 @@ using parse_options = parse_options_t<char>;
 // (the macro supplies the parentheses). It expands to the standard [[unlikely]]
 // attribute when supported, otherwise to __builtin_expect on GCC/Clang, or
 // to a no-op elsewhere (e.g. pre-C++20 MSVC, which has no equivalent hint).
+#if (defined(__cplusplus) && __cplusplus >= 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG >= 202002L)
 #ifdef __has_cpp_attribute
 #if __has_cpp_attribute(unlikely) >= 201803L
 // g++-9 hits hits this branch, but then fails to compile
@@ -266,6 +267,7 @@ using parse_options = parse_options_t<char>;
 #endif
 #endif
 #endif
+#endif
 
 #ifdef FASTFLOAT_USE_UNLIKELY_ATTR
 #define fastfloat_unlikely(x) (x) [[unlikely]]