diff --git a/test/unit_test/static/si_cgs_test.cpp b/test/unit_test/static/si_cgs_test.cpp
index 977a06e3..1bfcba8c 100644
--- a/test/unit_test/static/si_cgs_test.cpp
+++ b/test/unit_test/static/si_cgs_test.cpp
@@ -45,12 +45,12 @@ namespace {
 
 using namespace units::physical;
 
-static_assert(units::detail::quantity_ratio(si::length<si::metre>(1)) == units::ratio(1));
-static_assert(units::detail::quantity_ratio(si::cgs::length<si::cgs::centimetre>(1)) == units::ratio(1, 100));
-static_assert(units::detail::quantity_ratio(si::speed<si::metre_per_second>(1)) == units::ratio(1));
-static_assert(units::detail::quantity_ratio(si::cgs::speed<si::cgs::centimetre_per_second>(1)) == units::ratio(1, 100));
-static_assert(units::detail::quantity_ratio(si::force<si::newton>(1)) == units::ratio(1000));   // defined in terms of kilogram that are 1000 * gram
-static_assert(units::detail::quantity_ratio(si::cgs::force<si::cgs::dyne>(1)) == units::ratio(1, 100)); // defined in terms of gram so only centimetre ratio counts here
+static_assert(units::detail::quantity_ratio<si::length<si::metre>> == units::ratio(1));
+static_assert(units::detail::quantity_ratio<si::cgs::length<si::cgs::centimetre>> == units::ratio(1, 100));
+static_assert(units::detail::quantity_ratio<si::speed<si::metre_per_second>> == units::ratio(1));
+static_assert(units::detail::quantity_ratio<si::cgs::speed<si::cgs::centimetre_per_second>> == units::ratio(1, 100));
+static_assert(units::detail::quantity_ratio<si::force<si::newton>> == units::ratio(1000));   // defined in terms of kilogram that are 1000 * gram
+static_assert(units::detail::quantity_ratio<si::cgs::force<si::cgs::dyne>> == units::ratio(1, 100)); // defined in terms of gram so only centimetre ratio counts here
 
 static_assert(si::cgs::length<si::cgs::centimetre>(100) == si::length<si::metre>(1));
 static_assert(si::cgs::mass<si::cgs::gram>(1'000) == si::mass<si::kilogram>(1));