diff --git a/src/core/include/mp-units/framework/dimension.h b/src/core/include/mp-units/framework/dimension.h
index 1e5ec03c..c08fbefa 100644
--- a/src/core/include/mp-units/framework/dimension.h
+++ b/src/core/include/mp-units/framework/dimension.h
@@ -309,7 +309,7 @@ constexpr auto dimension_symbol_result = dimension_symbol_impl<fmt, CharT>(D{});
 // TODO Refactor to `dimension_symbol(D, fmt)` when P1045: constexpr Function Parameters is available
 MP_UNITS_EXPORT template<dimension_symbol_formatting fmt = dimension_symbol_formatting{}, typename CharT = char,
                          Dimension D>
-[[nodiscard]] consteval std::string_view dimension_symbol(D)
+[[nodiscard]] consteval std::basic_string_view<CharT> dimension_symbol(D)
 {
   return detail::dimension_symbol_result<fmt, CharT, D>.view();
 }
diff --git a/src/core/include/mp-units/framework/unit.h b/src/core/include/mp-units/framework/unit.h
index dabe2e98..f8263f75 100644
--- a/src/core/include/mp-units/framework/unit.h
+++ b/src/core/include/mp-units/framework/unit.h
@@ -920,7 +920,7 @@ constexpr auto unit_symbol_result = unit_symbol_impl<fmt, CharT>(U{});
 
 // TODO Refactor to `unit_symbol(U, fmt)` when P1045: constexpr Function Parameters is available
 MP_UNITS_EXPORT template<unit_symbol_formatting fmt = unit_symbol_formatting{}, typename CharT = char, Unit U>
-[[nodiscard]] consteval std::string_view unit_symbol(U)
+[[nodiscard]] consteval std::basic_string_view<CharT> unit_symbol(U)
 {
   return detail::unit_symbol_result<fmt, CharT, U>.view();
 }