diff --git a/src/core/include/mp-units/quantity.h b/src/core/include/mp-units/quantity.h
index f35ff1cd..ccf8b80b 100644
--- a/src/core/include/mp-units/quantity.h
+++ b/src/core/include/mp-units/quantity.h
@@ -163,8 +163,8 @@ public:
   }
 
   template<Unit U>
-    requires detail::QuantityConvertibleTo<quantity, quantity<::mp_units::reference<quantity_spec, U{}>{}, Rep>>
-  [[nodiscard]] constexpr quantity<::mp_units::reference<quantity_spec, U{}>{}, Rep> in(U) const
+    requires detail::QuantityConvertibleTo<quantity, quantity<quantity_spec[U{}], Rep>>
+  [[nodiscard]] constexpr quantity<quantity_spec[U{}], Rep> in(U) const
   {
     return quantity<quantity_spec[U{}], Rep>{*this};
   }
diff --git a/test/unit_test/static/quantity_test.cpp b/test/unit_test/static/quantity_test.cpp
index 0b49a559..0fdc13b3 100644
--- a/test/unit_test/static/quantity_test.cpp
+++ b/test/unit_test/static/quantity_test.cpp
@@ -200,6 +200,10 @@ static_assert(quantity<isq::length[km]>(1500 * m).numerical_value() == 1.5);
 // converting to a different unit
 ///////////////////////////////////
 
+static_assert(is_of_type<(2. * km).in(m), quantity<si::metre>>);
+static_assert(is_of_type<isq::length(2. * km).in(m), quantity<isq::length[m]>>);
+static_assert(is_of_type<isq::height(2. * km).in(m), quantity<isq::height[m]>>);
+
 static_assert(quantity<isq::length[km]>(2. * km).in(km).numerical_value() == 2.);
 static_assert(quantity<isq::length[km]>(2. * km).in(m).numerical_value() == 2000.);
 static_assert(quantity<isq::length[m]>(2000. * m).in(km).numerical_value() == 2.);