diff --git a/utest/quantity.test.cpp b/utest/quantity.test.cpp
index ea0e9712..4611ed8c 100644
--- a/utest/quantity.test.cpp
+++ b/utest/quantity.test.cpp
@@ -371,6 +371,57 @@ namespace xo {
             // /* milligrams:grams */
         } /*TEST_CASE(quantity.mult)*/
 
+        TEST_CASE("quantity.mult2", "[quantity.mult]") {
+            constexpr auto ms = qty::milliseconds(1.0);
+
+            /* proof that ms.s_unit is constexpr */
+            static_assert(ms.s_unit.n_bpu() == 1);
+
+            /* proof that ms.unit() is constexpr */
+            static_assert(ms.unit().n_bpu() == 1);
+
+            constexpr auto rr = detail::su_product<decltype(ms)::ratio_int_type, decltype(ms)::ratio_int2x_type>(ms.unit(), ms.unit());
+
+            /* proof that detail::su_product<..>(..) return value is constexpr */
+            static_assert(rr.outer_scale_sq_ == 1.0);
+            static_assert(rr.outer_scale_factor_.template convert_to<decltype(ms)::repr_type>() == 1.0);
+            static_assert(rr.natural_unit_.n_bpu() == 1);
+
+            constexpr auto q1 = quantity<decltype(ms)::repr_type,
+                                        decltype(ms)::ratio_int_type,
+                                        rr.natural_unit_,
+                                        decltype(ms)::ratio_int2x_type>(ms.scale() * ms.scale());
+
+            /* proof that q is constexpr */
+            static_assert(q1.scale() == 1.0);
+            static_assert(q1.unit().n_bpu() == 1);
+
+            {
+                using r_int_type = std::common_type_t<decltype(ms)::ratio_int_type,
+                                                      decltype(ms)::ratio_int_type>;
+                using r_int2x_type = std::common_type_t<decltype(ms)::ratio_int2x_type,
+                                                        decltype(ms)::ratio_int2x_type>;
+
+                constexpr auto rr = detail::su_product<r_int_type, r_int2x_type>(ms.unit(), ms.unit());
+
+                static_assert(rr.outer_scale_sq_ == 1.0);
+            }
+
+            constexpr auto q2 = quantity_util::multiply(ms, ms);
+
+            /* proof that q2 is constexpr */
+            static_assert(q2.scale() == 1.0);
+            static_assert(q2.unit().n_bpu() == 1);
+            static_assert(q2.unit()[0].power() == power_ratio_type(2,1));
+
+            constexpr auto q3 = ms * ms;
+
+            /* proof that q3 is constexpr */
+            static_assert(q3.scale() == 1.0);
+            static_assert(q3.unit().n_bpu() == 1);
+            static_assert(q3.unit()[0].power() == power_ratio_type(2,1));
+
+        } /*TEST_CASE(quantity.mult2)*/
     } /*namespace qty*/
 } /*namespace xo*/
 
diff --git a/utest/scaled_unit.test.cpp b/utest/scaled_unit.test.cpp
index d9b1d3d6..18cae503 100644
--- a/utest/scaled_unit.test.cpp
+++ b/utest/scaled_unit.test.cpp
@@ -70,7 +70,7 @@ namespace xo {
             }
         } /*TEST_CASE(su_product)*/
 
-        TEST_CASE("scaled_unit0", "[scaled_unit0]") {
+        TEST_CASE("scaled_unit0", "[scaled_unit]") {
             constexpr bool c_debug_flag = false;
 
             scope log(XO_DEBUG2(c_debug_flag, "TEST_CASE.scaled_unit0"));
@@ -85,7 +85,7 @@ namespace xo {
             static_assert(ng2.natural_unit_.n_bpu() == 1);
         } /*TEST_CASE(scaled_unit0)*/
 
-        TEST_CASE("scaled_unit1", "[scaled_unit1]") {
+        TEST_CASE("scaled_unit1", "[scaled_unit]") {
             constexpr bool c_debug_flag = false;
 
             scope log(XO_DEBUG2(c_debug_flag, "TEST_CASE.scaled_unit1"));
@@ -100,6 +100,21 @@ namespace xo {
             static_assert(ng2.natural_unit_.n_bpu() == 0);
         } /*TEST_CASE(scaled_unit1)*/
 
+        TEST_CASE("scaled_unit2", "[scaled_unit]") {
+            constexpr bool c_debug_flag = false;
+
+            scope log(XO_DEBUG2(c_debug_flag, "TEST_CASE.scaled_unit2"));
+
+            constexpr auto ms = su::millisecond;
+            constexpr auto ms2 = ms * ms;
+
+            log && log(xtag("ms", ms));
+            log && log(xtag("ms*ms", ms2));
+
+            static_assert(ms.natural_unit_.n_bpu() == 1);
+            static_assert(ms2.natural_unit_.n_bpu() == 1);
+        } /*TEST_CASE(scaled_unit2)*/
+
     } /*namespace qty*/
 } /*namespace xo*/