diff --git a/src/core/include/mp-units/framework/reference.h b/src/core/include/mp-units/framework/reference.h
index e2336fff..1ce19b70 100644
--- a/src/core/include/mp-units/framework/reference.h
+++ b/src/core/include/mp-units/framework/reference.h
@@ -49,9 +49,10 @@ using reference_t = reference<MP_UNITS_REMOVE_CONST(decltype(Q)), MP_UNITS_REMOV
 
 MP_UNITS_EXPORT_BEGIN
 
-[[nodiscard]] consteval QuantitySpec auto get_quantity_spec(AssociatedUnit auto u)
+template<AssociatedUnit U>
+[[nodiscard]] consteval QuantitySpec auto get_quantity_spec(U)
 {
-  return kind_of<detail::get_associated_quantity(u)>;
+  return kind_of<detail::get_associated_quantity(U{})>;
 }
 
 /**
diff --git a/src/core/include/mp-units/framework/reference_concepts.h b/src/core/include/mp-units/framework/reference_concepts.h
index 1d8077b0..775933af 100644
--- a/src/core/include/mp-units/framework/reference_concepts.h
+++ b/src/core/include/mp-units/framework/reference_concepts.h
@@ -34,7 +34,8 @@ struct reference;
 
 MP_UNITS_EXPORT_BEGIN
 
-[[nodiscard]] consteval QuantitySpec auto get_quantity_spec(AssociatedUnit auto u);
+template<AssociatedUnit U>
+[[nodiscard]] consteval QuantitySpec auto get_quantity_spec(U);
 
 template<typename Q, typename U>
 [[nodiscard]] consteval QuantitySpec auto get_quantity_spec(reference<Q, U>)