diff --git a/src/core/include/mp-units/unit.h b/src/core/include/mp-units/unit.h
index 86b50ee3d..0fb778333 100644
--- a/src/core/include/mp-units/unit.h
+++ b/src/core/include/mp-units/unit.h
@@ -821,7 +821,7 @@ template<typename CharT, std::size_t N, unit_symbol_formatting fmt, Unit U>
 
 // TODO Refactor to `unit_symbol(U, fmt)` when P1045: constexpr Function Parameters is available
 template<unit_symbol_formatting fmt = unit_symbol_formatting{}, typename CharT = char, Unit U>
-[[nodiscard]] constexpr auto unit_symbol(U)
+[[nodiscard]] consteval auto unit_symbol(U)
 {
   auto get_size = []() consteval {
     std::basic_string<CharT> buffer;