diff --git a/src/utility/include/mp_units/chrono.h b/src/utility/include/mp_units/chrono.h
index 18485c60..63925d14 100644
--- a/src/utility/include/mp_units/chrono.h
+++ b/src/utility/include/mp_units/chrono.h
@@ -60,7 +60,7 @@ template<typename Period>
 
 template<typename Rep, typename Period>
 struct quantity_like_traits<std::chrono::duration<Rep, Period>> {
-  static constexpr auto reference = isq::duration[detail::time_unit_from_chrono_period<Period>()];
+  static constexpr auto reference = detail::time_unit_from_chrono_period<Period>();
   using rep = Rep;
   [[nodiscard]] static constexpr rep number(const std::chrono::duration<Rep, Period>& q) { return q.count(); }
 };
@@ -75,7 +75,7 @@ inline constexpr chrono_point_origin_<C> chrono_point_origin;
 
 template<typename C, typename Rep, typename Period>
 struct quantity_point_like_traits<std::chrono::time_point<C, std::chrono::duration<Rep, Period>>> {
-  static constexpr auto reference = isq::time[detail::time_unit_from_chrono_period<Period>()];
+  static constexpr auto reference = detail::time_unit_from_chrono_period<Period>();
   static constexpr auto point_origin = chrono_point_origin<C>;
   using rep = Rep;
   [[nodiscard]] static constexpr auto relative(const std::chrono::time_point<C, std::chrono::duration<Rep, Period>>& qp)
diff --git a/test/unit_test/static/chrono_test.cpp b/test/unit_test/static/chrono_test.cpp
index 6886dc24..cbdd5d32 100644
--- a/test/unit_test/static/chrono_test.cpp
+++ b/test/unit_test/static/chrono_test.cpp
@@ -37,7 +37,7 @@ using sys_days =
   std::chrono::time_point<std::chrono::system_clock,
                           std::chrono::duration<long, std::ratio_multiply<std::ratio<24>, std::chrono::hours::period>>>;
 template<Unit auto U, typename C, typename Rep = double>
-using time_point = quantity_point<isq::time[U], chrono_point_origin<C>, Rep>;
+using time_point = quantity_point<U, chrono_point_origin<C>, Rep>;
 
 static_assert(QuantityLike<std::chrono::seconds>);
 static_assert(QuantityPointLike<sys_seconds>);
@@ -82,8 +82,8 @@ static_assert(!std::convertible_to<sys_seconds, time_point<si::day, std::chrono:
 
 
 // CTAD
-static_assert(is_of_type<quantity{1s}, quantity<isq::time[si::second], std::chrono::seconds::rep>>);
-static_assert(is_of_type<quantity{1h}, quantity<isq::time[si::hour], std::chrono::hours::rep>>);
+static_assert(is_of_type<quantity{1s}, quantity<si::second, std::chrono::seconds::rep>>);
+static_assert(is_of_type<quantity{1h}, quantity<si::hour, std::chrono::hours::rep>>);
 static_assert(
   is_of_type<quantity_point{sys_seconds{1s}}, time_point<si::second, std::chrono::system_clock, sys_seconds::rep>>);
 static_assert(is_of_type<quantity_point{sys_days{sys_days::duration{1}}},