diff --git a/doc/DESIGN.md b/doc/DESIGN.md
index 60f96d72..a341ce47 100644
--- a/doc/DESIGN.md
+++ b/doc/DESIGN.md
@@ -51,7 +51,7 @@ Quantity is a concrete amount of a unit for a specified dimension with a specifi
 
 ```cpp
 units::quantity<units::kilometer, double> d1(123);
-auto d2 = 123_km;    // units::quantity<units::kilometer, std::int64_t>
+auto d2 = 123_km;    // stde::units::quantity<units::kilometer, std::int64_t>
 ```
 
 There are C++ concepts provided for each such quantity type:
@@ -64,7 +64,7 @@ concept Length = Quantity<T> && std::Same<typename T::dimension, dimension_lengt
 With that we can easily write a function template like this:
 
 ```cpp
-constexpr units::Velocity auto avg_speed(units::Length auto d, units::Time auto t)
+constexpr stde::units::Velocity auto avg_speed(units::Length auto d,stde::units::Time auto t)
 {
   return d / t;
 }
@@ -316,7 +316,7 @@ could generate a following compile time error:
    const Velocity auto t = 20_s;
                            ^~~~
 In file included from <path>\example\example.cpp:23:
-<path>/src/include/units/si/velocity.h:41:16: note: within 'template<class T> concept const bool units::Velocity<T> [with T = units::quantity<units::unit<units::dimension<units::exp<units::base_dim_time, 1> >, std::ratio<1> >, long long int>]'
+<path>/src/include/units/si/velocity.h:41:16: note: within 'template<class T> concept const bool stde::units::Velocity<T> [with T = stde::units::quantity<units::unit<units::dimension<units::exp<units::base_dim_time, 1> >, std::ratio<1> >, long long int>]'
    concept Velocity = Quantity<T> && std::Same<typename T::dimension, dimension_velocity>;
            ^~~~~~~~
 In file included from <path>/src/include/units/bits/tools.h:25,
@@ -324,7 +324,7 @@ In file included from <path>/src/include/units/bits/tools.h:25,
                  from <path>/src/include/units/si/base_dimensions.h:25,
                  from <path>/src/include/units/si/velocity.h:25,
                  from <path>\example\example.cpp:23:
-<path>/src/include/units/bits/stdconcepts.h:33:18: note: within 'template<class T, class U> concept const bool std::Same<T, U> [with T = units::dimension<units::exp<units::base_dim_time, 1> >; U = units::dimension<units::exp<units::base_dim_length, 1>, units::exp<units::base_dim_time, -1> >]'
+<path>/src/include/units/bits/stdconcepts.h:33:18: note: within 'template<class T, class U> concept const bool std::Same<T, U> [with T = stde::units::dimension<units::exp<units::base_dim_time, 1> >; U = stde::units::dimension<units::exp<units::base_dim_length, 1>,stde::units::exp<units::base_dim_time, -1> >]'
      concept Same = std::is_same_v<T, U>;
              ^~~~
 <path>/src/include/units/bits/stdconcepts.h:33:18: note: 'std::is_same_v' evaluated to false
@@ -334,13 +334,13 @@ Time and velocity are not that complicated dimensions and there are much more co
 out there, but even for those dimensions
 
 ```text
-[with T = units::quantity<units::unit<units::dimension<units::exp<units::base_dim_time, 1> >, std::ratio<1> >, long long int>]
+[with T = stde::units::quantity<units::unit<units::dimension<units::exp<units::base_dim_time, 1> >, std::ratio<1> >, long long int>]
 ```
 
 and
 
 ```text
-[with T = units::dimension<units::exp<units::base_dim_time, 1> >; U = units::dimension<units::exp<units::base_dim_length, 1>, units::exp<units::base_dim_time, -1> >]
+[with T = stde::units::dimension<units::exp<units::base_dim_time, 1> >; U = stde::units::dimension<units::exp<units::base_dim_length, 1>,stde::units::exp<units::base_dim_time, -1> >]
 ```
 
 starts to be really hard to analyze or debug.
@@ -353,7 +353,7 @@ same code will result with such an error:
    const Velocity t = 20_s;
                       ^~~~
 In file included from <path>\example\example.cpp:23:
-<path>/src/include/units/si/velocity.h:48:16: note: within 'template<class T> concept const bool units::Velocity<T> [with T = units::quantity<units::second, long long int>]'
+<path>/src/include/units/si/velocity.h:48:16: note: within 'template<class T> concept const bool stde::units::Velocity<T> [with T = stde::units::quantity<units::second, long long int>]'
    concept Velocity = Quantity<T> && std::Same<typename T::dimension, dimension_velocity>;
            ^~~~~~~~
 In file included from <path>/src/include/units/bits/tools.h:25,
@@ -361,7 +361,7 @@ In file included from <path>/src/include/units/bits/tools.h:25,
                  from <path>/src/include/units/si/base_dimensions.h:25,
                  from <path>/src/include/units/si/velocity.h:25,
                  from <path>\example\example.cpp:23:
-<path>/src/include/units/bits/stdconcepts.h:33:18: note: within 'template<class T, class U> concept const bool std::Same<T, U> [with T = units::dimension_time; U = units::dimension_velocity]'
+<path>/src/include/units/bits/stdconcepts.h:33:18: note: within 'template<class T, class U> concept const bool std::Same<T, U> [with T = stde::units::dimension_time; U = stde::units::dimension_velocity]'
      concept Same = std::is_same_v<T, U>;
              ^~~~
 <path>/src/include/units/bits/stdconcepts.h:33:18: note: 'std::is_same_v' evaluated to false
@@ -370,13 +370,13 @@ In file included from <path>/src/include/units/bits/tools.h:25,
 Now
 
 ```text
-[with T = units::quantity<units::second, long long int>]
+[with T = stde::units::quantity<units::second, long long int>]
 ```
 
 and
 
 ```text
-[with T = units::dimension_time; U = units::dimension_velocity]
+[with T = stde::units::dimension_time; U = stde::units::dimension_velocity]
 ```
 
 are not arguably much easier to understand thus provide better user experience.
diff --git a/example/example.cpp b/example/example.cpp
index 633b287a..598d61ed 100644
--- a/example/example.cpp
+++ b/example/example.cpp
@@ -25,26 +25,27 @@
 
 namespace {
 
-using namespace units::literals;
+namespace stde = std::experimental;
+using namespace stde::units::literals;
 
-template<units::Length D, units::Time T>
-constexpr units::Velocity avg_speed(D d, T t)
+template<stde::units::Length D, stde::units::Time T>
+constexpr stde::units::Velocity avg_speed(D d, T t)
 {
   return d / t;
 }
 
-template<units::Velocity V, units::Time T>
+template<stde::units::Velocity V, stde::units::Time T>
 void example_1(V v, T t)
 {
-  const units::Length distance = v * t;
+  const stde::units::Length distance = v * t;
   std::cout << "A car driving " << v.count() << " km/h in a time of " << t.count() << " minutes will pass "
-            << units::quantity_cast<units::quantity<units::meter, double>>(distance).count() << " meters.\n";
+            << stde::units::quantity_cast<stde::units::quantity<stde::units::meter, double>>(distance).count() << " meters.\n";
 }
 
 void example_2(double distance_v, double duration_v)
 {
-  units::quantity<units::kilometer> distance(distance_v);
-  units::quantity<units::hour> duration(duration_v);
+  stde::units::quantity<stde::units::kilometer> distance(distance_v);
+  stde::units::quantity<stde::units::hour> duration(duration_v);
   const auto kmph = avg_speed(distance, duration);
   std::cout << "Average speed of a car that makes " << distance.count() << " km in "
             << duration.count() << " hours is " << kmph.count() << " km/h.\n";
diff --git a/src/include/units/area.h b/src/include/units/area.h
index 9e8abbef..14619490 100644
--- a/src/include/units/area.h
+++ b/src/include/units/area.h
@@ -24,7 +24,7 @@
 
 #include <units/length.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_area : make_dimension_t<exp<base_dim_length, 2>> {};
   template<> struct downcasting_traits<downcast_from<dimension_area>> : downcast_to<dimension_area> {};
@@ -67,4 +67,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/base_dimensions.h b/src/include/units/base_dimensions.h
index 293bb227..2d71c329 100644
--- a/src/include/units/base_dimensions.h
+++ b/src/include/units/base_dimensions.h
@@ -24,7 +24,7 @@
 
 #include <units/dimension.h>
 
-namespace units {
+namespace std::experimental::units {
 
   // todo: to be replaced with fixed_string when supported by the compilers
 
@@ -36,4 +36,4 @@ namespace units {
   struct base_dim_substance : dim_id<5> {};
   struct base_dim_luminous_intensity : dim_id<6> {};
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/bits/concepts.h b/src/include/units/bits/concepts.h
index 1f32d003..b018eec7 100644
--- a/src/include/units/bits/concepts.h
+++ b/src/include/units/bits/concepts.h
@@ -24,7 +24,7 @@
 
 #include <units/bits/hacks.h>
 
-namespace units {
+namespace std::experimental::units {
 
   template<typename T>
   concept bool Number = std::Regular<T> &&
@@ -43,4 +43,4 @@ namespace units {
         // …
   } ;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/bits/downcasting.h b/src/include/units/bits/downcasting.h
index b6e89620..958efbfc 100644
--- a/src/include/units/bits/downcasting.h
+++ b/src/include/units/bits/downcasting.h
@@ -25,7 +25,7 @@
 #include <units/bits/hacks.h>
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   template<typename BaseType>
   struct downcast_base {
@@ -51,4 +51,4 @@ namespace units {
   template<Downcastable T>
   using downcasting_traits_t = downcasting_traits<T>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/bits/type_list.h b/src/include/units/bits/type_list.h
index 98275446..2e611926 100644
--- a/src/include/units/bits/type_list.h
+++ b/src/include/units/bits/type_list.h
@@ -24,7 +24,7 @@
 
 #include <units/bits/type_traits.h>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -182,4 +182,4 @@ namespace units {
   template<TypeList List, template<typename, typename> typename Pred>
   using type_list_sort = detail::type_list_sort_impl<List, Pred>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/bits/type_traits.h b/src/include/units/bits/type_traits.h
index 4a9c8a50..a2928c5b 100644
--- a/src/include/units/bits/type_traits.h
+++ b/src/include/units/bits/type_traits.h
@@ -24,7 +24,7 @@
 
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
diff --git a/src/include/units/current.h b/src/include/units/current.h
index 6011a1ef..a7a62e31 100644
--- a/src/include/units/current.h
+++ b/src/include/units/current.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/quantity.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_current : make_dimension_t<exp<base_dim_current, 1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_current>> : downcast_to<dimension_current> {};
@@ -44,4 +44,4 @@ namespace units {
 
   }
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/dimension.h b/src/include/units/dimension.h
index c27aff4f..57646242 100644
--- a/src/include/units/dimension.h
+++ b/src/include/units/dimension.h
@@ -25,7 +25,7 @@
 #include <units/bits/type_list.h>
 #include <units/bits/downcasting.h>
 
-namespace units {
+namespace std::experimental::units {
 
   // dim_id
 
@@ -186,4 +186,4 @@ namespace units {
   template<Dimension D1, Dimension D2>
   using dimension_divide_t = dimension_divide<typename D1::base_type, typename D2::base_type>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/frequency.h b/src/include/units/frequency.h
index d4625a92..1196a71b 100644
--- a/src/include/units/frequency.h
+++ b/src/include/units/frequency.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/time.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_frequency : make_dimension_t<exp<base_dim_time, -1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_frequency>> : downcast_to<dimension_frequency> {};
@@ -79,4 +79,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/length.h b/src/include/units/length.h
index fa43b527..0a7e9e20 100644
--- a/src/include/units/length.h
+++ b/src/include/units/length.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/quantity.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_length : make_dimension_t<exp<base_dim_length, 1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_length>> : downcast_to<dimension_length> {};
@@ -99,4 +99,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/luminous_intensity.h b/src/include/units/luminous_intensity.h
index 338d634b..dc597645 100644
--- a/src/include/units/luminous_intensity.h
+++ b/src/include/units/luminous_intensity.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/quantity.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_luminous_intensity : make_dimension_t<exp<base_dim_luminous_intensity, 1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_luminous_intensity>> : downcast_to<dimension_luminous_intensity> {};
@@ -44,4 +44,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/mass.h b/src/include/units/mass.h
index b0515980..f5a17729 100644
--- a/src/include/units/mass.h
+++ b/src/include/units/mass.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/quantity.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_mass : make_dimension_t<exp<base_dim_mass, 1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_mass>> : downcast_to<dimension_mass> {};
@@ -51,4 +51,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/quantity.h b/src/include/units/quantity.h
index 4e0d4ba2..77bb3fb0 100644
--- a/src/include/units/quantity.h
+++ b/src/include/units/quantity.h
@@ -27,7 +27,7 @@
 #include <limits>
 #include <gsl/gsl-lite.hpp>
 
-namespace units {
+namespace std::experimental::units {
 
   // is_quantity
   namespace detail {
@@ -408,4 +408,4 @@ namespace units {
     return !(lhs < rhs);
   }
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/ratio.h b/src/include/units/ratio.h
index eca4333d..32f53faa 100644
--- a/src/include/units/ratio.h
+++ b/src/include/units/ratio.h
@@ -27,7 +27,7 @@
 #include <cstdint>
 #include <gsl/gsl-lite.hpp>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -135,4 +135,4 @@ namespace units {
   template<Ratio R1, Ratio R2>
   using common_ratio = typename detail::common_ratio_impl<R1, R2>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/substance.h b/src/include/units/substance.h
index 9a44590c..11baf372 100644
--- a/src/include/units/substance.h
+++ b/src/include/units/substance.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/quantity.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_substance : make_dimension_t<exp<base_dim_substance, 1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_substance>> : downcast_to<dimension_substance> {};
@@ -44,4 +44,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/temperature.h b/src/include/units/temperature.h
index 3f69403e..8e040ca1 100644
--- a/src/include/units/temperature.h
+++ b/src/include/units/temperature.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/quantity.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_temperature : make_dimension_t<exp<base_dim_temperature, 1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_temperature>> : downcast_to<dimension_temperature> {};
@@ -44,4 +44,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/time.h b/src/include/units/time.h
index 950730be..372bc1d7 100644
--- a/src/include/units/time.h
+++ b/src/include/units/time.h
@@ -25,7 +25,7 @@
 #include <units/base_dimensions.h>
 #include <units/quantity.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_time : make_dimension_t<exp<base_dim_time, 1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_time>> : downcast_to<dimension_time> {};
@@ -79,4 +79,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/unit.h b/src/include/units/unit.h
index 9b261889..f2f85c91 100644
--- a/src/include/units/unit.h
+++ b/src/include/units/unit.h
@@ -26,7 +26,7 @@
 #include <units/ratio.h>
 #include <ratio>
 
-namespace units {
+namespace std::experimental::units {
 
   template<Dimension D, Ratio R = ratio<1>>
     requires (R::num > 0)
@@ -68,7 +68,7 @@ namespace units {
 
     template<typename BaseDimension, Unit... Us>
     struct get_ratio {
-      using ratio = ::units::ratio<1>;
+      using ratio = ::std::experimental::units::ratio<1>;
     };
 
     template<typename BaseDimension, Unit U, Unit... Rest>
@@ -99,7 +99,7 @@ namespace units {
 
     template<Unit... Us>
     struct derived_ratio<dimension<>, Us...> {
-      using ratio = ::units::ratio<1>;
+      using ratio = ::std::experimental::units::ratio<1>;
     };
 
     template<Exponent E, Exponent... Rest, Unit... Us>
@@ -131,4 +131,4 @@ namespace units {
   template<Unit U> using peta = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::peta::num>>>;
   template<Unit U> using exa = unit<typename U::dimension, ratio_multiply<typename U::ratio, ratio<std::exa::num>>>;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/src/include/units/velocity.h b/src/include/units/velocity.h
index 69b7b5f0..419ab7e1 100644
--- a/src/include/units/velocity.h
+++ b/src/include/units/velocity.h
@@ -25,7 +25,7 @@
 #include <units/length.h>
 #include <units/time.h>
 
-namespace units {
+namespace std::experimental::units {
 
   struct dimension_velocity : make_dimension_t<exp<base_dim_length, 1>, exp<base_dim_time, -1>> {};
   template<> struct downcasting_traits<downcast_from<dimension_velocity>> : downcast_to<dimension_velocity> {};
@@ -58,4 +58,4 @@ namespace units {
 
   }  // namespace literals
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/metabench/list/type_list_concepts_all.cpp.erb b/test/metabench/list/type_list_concepts_all.cpp.erb
index 8aacaafe..88c33108 100644
--- a/test/metabench/list/type_list_concepts_all.cpp.erb
+++ b/test/metabench/list/type_list_concepts_all.cpp.erb
@@ -6,6 +6,7 @@ using dim_id = std::integral_constant<int, UniqueValue>;
 template<typename D1, typename D2>
 using dim_id_less = std::bool_constant<D1::value < D2::value>;
 
+namespace stde = std::experimental;
 
 template<typename... Es>
 struct dimension;
@@ -20,7 +21,7 @@ using <%= "dim#{i}" %> = dimension<<%=
     xs.shuffle(random: rng).join(', ')
 %>>;
 #if defined(METABENCH)
-using <%= "result#{i}" %> = units::type_list_sort_t<<%= "dim#{i}" %>, dim_id_less>;
+using <%= "result#{i}" %> = stde::units::type_list_sort_t<<%= "dim#{i}" %>, dim_id_less>;
 #endif
 <% end %>
 
diff --git a/test/metabench/list/type_list_concepts_all.h b/test/metabench/list/type_list_concepts_all.h
index 3f0a4746..a0a17d0f 100644
--- a/test/metabench/list/type_list_concepts_all.h
+++ b/test/metabench/list/type_list_concepts_all.h
@@ -24,7 +24,7 @@
 
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -182,4 +182,4 @@ namespace units {
   template<TypeList List, template<typename, typename> typename Pred>
   using type_list_sort_t = type_list_sort<List, Pred>::type;
 
-}  // namespace units
\ No newline at end of file
+}  // namespace std::experimental::units
\ No newline at end of file
diff --git a/test/metabench/list/type_list_concepts_iface.cpp.erb b/test/metabench/list/type_list_concepts_iface.cpp.erb
index 4b89f825..ac5b688f 100644
--- a/test/metabench/list/type_list_concepts_iface.cpp.erb
+++ b/test/metabench/list/type_list_concepts_iface.cpp.erb
@@ -1,5 +1,7 @@
 #include "type_list_concepts_iface.h"
 
+namespace stde = std::experimental;
+
 template<int UniqueValue>
 using dim_id = std::integral_constant<int, UniqueValue>;
 
@@ -20,7 +22,7 @@ using <%= "dim#{i}" %> = dimension<<%=
     xs.shuffle(random: rng).join(', ')
 %>>;
 #if defined(METABENCH)
-using <%= "result#{i}" %> = units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
+using <%= "result#{i}" %> = stde::units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
 #endif
 <% end %>
 
diff --git a/test/metabench/list/type_list_concepts_iface.h b/test/metabench/list/type_list_concepts_iface.h
index 056ba4f2..0fe3a290 100644
--- a/test/metabench/list/type_list_concepts_iface.h
+++ b/test/metabench/list/type_list_concepts_iface.h
@@ -24,7 +24,7 @@
 
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -201,4 +201,4 @@ namespace units {
   template<TypeList List, template<typename, typename> typename Pred>
   using type_list_sort = detail::type_list_sort_impl<List, Pred>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/metabench/list/type_list_concepts_no.cpp.erb b/test/metabench/list/type_list_concepts_no.cpp.erb
index 4adbf45e..3ac9d567 100644
--- a/test/metabench/list/type_list_concepts_no.cpp.erb
+++ b/test/metabench/list/type_list_concepts_no.cpp.erb
@@ -1,5 +1,7 @@
 #include "type_list_concepts_no.h"
 
+namespace stde = std::experimental;
+
 template<int UniqueValue>
 using dim_id = std::integral_constant<int, UniqueValue>;
 
@@ -20,7 +22,7 @@ using <%= "dim#{i}" %> = dimension<<%=
     xs.shuffle(random: rng).join(', ')
 %>>;
 #if defined(METABENCH)
-using <%= "result#{i}" %> = units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
+using <%= "result#{i}" %> = stde::units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
 #endif
 <% end %>
 
diff --git a/test/metabench/list/type_list_concepts_no.h b/test/metabench/list/type_list_concepts_no.h
index ab74a04e..4c24c039 100644
--- a/test/metabench/list/type_list_concepts_no.h
+++ b/test/metabench/list/type_list_concepts_no.h
@@ -24,7 +24,7 @@
 
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -188,4 +188,4 @@ namespace units {
   template<typename List, template<typename, typename> typename Pred>
   using type_list_sort = detail::type_list_sort_impl<List, Pred>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/metabench/list/type_list_conditional_alias.cpp.erb b/test/metabench/list/type_list_conditional_alias.cpp.erb
index 80bf8526..eafda990 100644
--- a/test/metabench/list/type_list_conditional_alias.cpp.erb
+++ b/test/metabench/list/type_list_conditional_alias.cpp.erb
@@ -1,5 +1,7 @@
 #include "type_list_conditional_alias.h"
 
+namespace stde = std::experimental;
+
 template<int UniqueValue>
 using dim_id = std::integral_constant<int, UniqueValue>;
 
@@ -20,7 +22,7 @@ using <%= "dim#{i}" %> = dimension<<%=
     xs.shuffle(random: rng).join(', ')
 %>>;
 #if defined(METABENCH)
-using <%= "result#{i}" %> = units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
+using <%= "result#{i}" %> = stde::units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
 #endif
 <% end %>
 
diff --git a/test/metabench/list/type_list_conditional_alias.h b/test/metabench/list/type_list_conditional_alias.h
index 056ba4f2..0fe3a290 100644
--- a/test/metabench/list/type_list_conditional_alias.h
+++ b/test/metabench/list/type_list_conditional_alias.h
@@ -24,7 +24,7 @@
 
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -201,4 +201,4 @@ namespace units {
   template<TypeList List, template<typename, typename> typename Pred>
   using type_list_sort = detail::type_list_sort_impl<List, Pred>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/metabench/list/type_list_conditional_alias_hard.cpp.erb b/test/metabench/list/type_list_conditional_alias_hard.cpp.erb
index 837a0a47..b22938bc 100644
--- a/test/metabench/list/type_list_conditional_alias_hard.cpp.erb
+++ b/test/metabench/list/type_list_conditional_alias_hard.cpp.erb
@@ -1,5 +1,7 @@
 #include "type_list_conditional_alias_hard.h"
 
+namespace stde = std::experimental;
+
 template<int UniqueValue>
 using dim_id = std::integral_constant<int, UniqueValue>;
 
@@ -20,7 +22,7 @@ using <%= "dim#{i}" %> = dimension<<%=
     xs.shuffle(random: rng).join(', ')
 %>>;
 #if defined(METABENCH)
-using <%= "result#{i}" %> = units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
+using <%= "result#{i}" %> = stde::units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
 #endif
 <% end %>
 
diff --git a/test/metabench/list/type_list_conditional_alias_hard.h b/test/metabench/list/type_list_conditional_alias_hard.h
index c6b43d43..556ae9bd 100644
--- a/test/metabench/list/type_list_conditional_alias_hard.h
+++ b/test/metabench/list/type_list_conditional_alias_hard.h
@@ -24,7 +24,7 @@
 
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   template<bool>
   struct conditional {
@@ -194,4 +194,4 @@ namespace units {
   template<TypeList List, template<typename, typename> typename Pred>
   using type_list_sort = detail::type_list_sort_impl<List, Pred>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/metabench/list/type_list_conditional_std.cpp.erb b/test/metabench/list/type_list_conditional_std.cpp.erb
index 8c9a1f95..50535cd9 100644
--- a/test/metabench/list/type_list_conditional_std.cpp.erb
+++ b/test/metabench/list/type_list_conditional_std.cpp.erb
@@ -1,5 +1,7 @@
 #include "type_list_conditional_std.h"
 
+namespace stde = std::experimental;
+
 template<int UniqueValue>
 using dim_id = std::integral_constant<int, UniqueValue>;
 
@@ -20,7 +22,7 @@ using <%= "dim#{i}" %> = dimension<<%=
     xs.shuffle(random: rng).join(', ')
 %>>;
 #if defined(METABENCH)
-using <%= "result#{i}" %> = units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
+using <%= "result#{i}" %> = stde::units::type_list_sort<<%= "dim#{i}" %>, dim_id_less>;
 #endif
 <% end %>
 
diff --git a/test/metabench/list/type_list_conditional_std.h b/test/metabench/list/type_list_conditional_std.h
index 54e0a100..5600f16b 100644
--- a/test/metabench/list/type_list_conditional_std.h
+++ b/test/metabench/list/type_list_conditional_std.h
@@ -24,7 +24,7 @@
 
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -182,4 +182,4 @@ namespace units {
   template<TypeList List, template<typename, typename> typename Pred>
   using type_list_sort = detail::type_list_sort_impl<List, Pred>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/metabench/ratio/all_ratio_type_constexpr.cpp.erb b/test/metabench/ratio/all_ratio_type_constexpr.cpp.erb
index cff47d9e..2e98e10d 100644
--- a/test/metabench/ratio/all_ratio_type_constexpr.cpp.erb
+++ b/test/metabench/ratio/all_ratio_type_constexpr.cpp.erb
@@ -1,15 +1,17 @@
 #include "ratio_type_constexpr.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
 #if defined(METABENCH)
-    using r1 = units::ratio<<%= i %>, <%= n + 1 - i %>>;
-    using r2 = units::ratio<<%= n + 1 - i %>, <%= i %>>;
+    using r1 = stde::units::ratio<<%= i %>, <%= n + 1 - i %>>;
+    using r2 = stde::units::ratio<<%= n + 1 - i %>, <%= i %>>;
 
-    using r3 = units::ratio_multiply<r1, r2>;
-    using r4 = units::ratio_divide<r1, r2>;
+    using r3 = stde::units::ratio_multiply<r1, r2>;
+    using r4 = stde::units::ratio_divide<r1, r2>;
 
-    using r5 = units::common_ratio_t<r1, r2>;
+    using r5 = stde::units::common_ratio_t<r1, r2>;
 #endif
   };
 <% end %>
diff --git a/test/metabench/ratio/all_std_ratio.cpp.erb b/test/metabench/ratio/all_std_ratio.cpp.erb
index 851b7256..0848d4f9 100644
--- a/test/metabench/ratio/all_std_ratio.cpp.erb
+++ b/test/metabench/ratio/all_std_ratio.cpp.erb
@@ -1,5 +1,7 @@
 #include "std_ratio.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
 #if defined(METABENCH)
@@ -9,7 +11,7 @@
     using r3 = std::ratio_multiply<r1, r2>;
     using r4 = std::ratio_divide<r1, r2>;
 
-    using r5 = units::common_ratio_t<r1, r2>;
+    using r5 = stde::units::common_ratio_t<r1, r2>;
 #endif
   };
 <% end %>
diff --git a/test/metabench/ratio/common_ratio_ratio_type_constexpr.cpp.erb b/test/metabench/ratio/common_ratio_ratio_type_constexpr.cpp.erb
index ec680850..89c5a6a1 100644
--- a/test/metabench/ratio/common_ratio_ratio_type_constexpr.cpp.erb
+++ b/test/metabench/ratio/common_ratio_ratio_type_constexpr.cpp.erb
@@ -1,15 +1,17 @@
 #include "ratio_type_constexpr.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
-    using r1 = units::ratio<<%= i %>, <%= n + 1 - i %>>;
-    using r2 = units::ratio<<%= n + 1 - i %>, <%= i %>>;
+    using r1 = stde::units::ratio<<%= i %>, <%= n + 1 - i %>>;
+    using r2 = stde::units::ratio<<%= n + 1 - i %>, <%= i %>>;
 
-    using r3 = units::ratio_multiply<r1, r2>;
-    using r4 = units::ratio_divide<r1, r2>;
+    using r3 = stde::units::ratio_multiply<r1, r2>;
+    using r4 = stde::units::ratio_divide<r1, r2>;
 
 #if defined(METABENCH)
-    using r5 = units::common_ratio_t<r1, r2>;
+    using r5 = stde::units::common_ratio_t<r1, r2>;
 #endif
   };
 <% end %>
diff --git a/test/metabench/ratio/common_ratio_std_ratio.cpp.erb b/test/metabench/ratio/common_ratio_std_ratio.cpp.erb
index 5da2d0a0..3df70151 100644
--- a/test/metabench/ratio/common_ratio_std_ratio.cpp.erb
+++ b/test/metabench/ratio/common_ratio_std_ratio.cpp.erb
@@ -1,5 +1,7 @@
 #include "std_ratio.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
     using r1 = std::ratio<<%= i %>, <%= n + 1 - i %>>;
@@ -9,7 +11,7 @@
     using r4 = std::ratio_divide<r1, r2>;
 
 #if defined(METABENCH)
-    using r5 = units::common_ratio_t<r1, r2>;
+    using r5 = stde::units::common_ratio_t<r1, r2>;
 #endif
   };
 <% end %>
diff --git a/test/metabench/ratio/create_ratio_type_constexpr.cpp.erb b/test/metabench/ratio/create_ratio_type_constexpr.cpp.erb
index 80fa9e72..918e50b8 100644
--- a/test/metabench/ratio/create_ratio_type_constexpr.cpp.erb
+++ b/test/metabench/ratio/create_ratio_type_constexpr.cpp.erb
@@ -1,10 +1,12 @@
 #include "ratio_type_constexpr.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
 #if defined(METABENCH)
-    using r1 = units::ratio<<%= i %>, <%= n + 1 - i %>>;
-    using r2 = units::ratio<<%= n + 1 - i %>, <%= i %>>;
+    using r1 = stde::units::ratio<<%= i %>, <%= n + 1 - i %>>;
+    using r2 = stde::units::ratio<<%= n + 1 - i %>, <%= i %>>;
 #endif
   };
 <% end %>
diff --git a/test/metabench/ratio/create_std_ratio.cpp.erb b/test/metabench/ratio/create_std_ratio.cpp.erb
index 3555aab8..038325e4 100644
--- a/test/metabench/ratio/create_std_ratio.cpp.erb
+++ b/test/metabench/ratio/create_std_ratio.cpp.erb
@@ -1,5 +1,7 @@
 #include "std_ratio.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
 #if defined(METABENCH)
diff --git a/test/metabench/ratio/multiply_divide_ratio_type_constexpr.cpp.erb b/test/metabench/ratio/multiply_divide_ratio_type_constexpr.cpp.erb
index d7c4d98f..18499cb7 100644
--- a/test/metabench/ratio/multiply_divide_ratio_type_constexpr.cpp.erb
+++ b/test/metabench/ratio/multiply_divide_ratio_type_constexpr.cpp.erb
@@ -1,13 +1,15 @@
 #include "ratio_type_constexpr.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
-    using r1 = units::ratio<<%= i %>, <%= n + 1 - i %>>;
-    using r2 = units::ratio<<%= n + 1 - i %>, <%= i %>>;
+    using r1 = stde::units::ratio<<%= i %>, <%= n + 1 - i %>>;
+    using r2 = stde::units::ratio<<%= n + 1 - i %>, <%= i %>>;
 
 #if defined(METABENCH)
-    using r3 = units::ratio_multiply<r1, r2>;
-    using r4 = units::ratio_divide<r1, r2>;
+    using r3 = stde::units::ratio_multiply<r1, r2>;
+    using r4 = stde::units::ratio_divide<r1, r2>;
 #endif
   };
 <% end %>
diff --git a/test/metabench/ratio/multiply_divide_std_ratio.cpp.erb b/test/metabench/ratio/multiply_divide_std_ratio.cpp.erb
index 0216d2ea..0ae19648 100644
--- a/test/metabench/ratio/multiply_divide_std_ratio.cpp.erb
+++ b/test/metabench/ratio/multiply_divide_std_ratio.cpp.erb
@@ -1,5 +1,7 @@
 #include "std_ratio.h"
 
+namespace stde = std::experimental;
+
 <% (1..n).each do |i| %>
   struct test<%= i %> {
     using r1 = std::ratio<<%= i %>, <%= n + 1 - i %>>;
diff --git a/test/metabench/ratio/ratio_type_constexpr.h b/test/metabench/ratio/ratio_type_constexpr.h
index 90b6cbf7..f344a168 100644
--- a/test/metabench/ratio/ratio_type_constexpr.h
+++ b/test/metabench/ratio/ratio_type_constexpr.h
@@ -27,7 +27,7 @@
 #include <cstdint>
 #include <gsl/gsl-lite.hpp>
 
-namespace units {
+namespace std::experimental::units {
 
   namespace detail {
 
@@ -120,4 +120,4 @@ namespace units {
   template<typename R1, typename R2>
   using common_ratio_t = typename detail::common_ratio_impl<R1, R2>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/metabench/ratio/std_ratio.h b/test/metabench/ratio/std_ratio.h
index 45422fe9..8e7d49e8 100644
--- a/test/metabench/ratio/std_ratio.h
+++ b/test/metabench/ratio/std_ratio.h
@@ -25,7 +25,7 @@
 #include <ratio>
 #include <type_traits>
 
-namespace units {
+namespace std::experimental::units {
 
   // static_sign
 
@@ -66,4 +66,4 @@ namespace units {
   template<typename R1, typename R2>
   using common_ratio_t = typename common_ratio<R1, R2>::type;
 
-}  // namespace units
+}  // namespace std::experimental::units
diff --git a/test/unit_test/test_dimension.cpp b/test/unit_test/test_dimension.cpp
index dd09d602..8b637224 100644
--- a/test/unit_test/test_dimension.cpp
+++ b/test/unit_test/test_dimension.cpp
@@ -23,7 +23,7 @@
 #include "units/dimension.h"
 #include <utility>
 
-using namespace units;
+using namespace std::experimental::units;
 
 namespace {
 
diff --git a/test/unit_test/test_quantity.cpp b/test/unit_test/test_quantity.cpp
index 4f2a10f4..f8d5f498 100644
--- a/test/unit_test/test_quantity.cpp
+++ b/test/unit_test/test_quantity.cpp
@@ -25,7 +25,7 @@
 #include <utility>
 #include <chrono>
 
-using namespace units;
+using namespace std::experimental::units;
 
 namespace {
 
@@ -44,7 +44,7 @@ namespace {
 
 }  // namespace
 
-namespace units {
+namespace std::experimental::units {
 
   template<typename T>
   inline constexpr bool treat_as_floating_point<my_value<T>> = std::is_floating_point_v<T>;
@@ -56,7 +56,7 @@ namespace units {
     static constexpr my_value<T> min() { return std::numeric_limits<T>::lowest(); }
   };
 
-}  // namespace units
+}  // namespace std::experimental::units
 
 namespace std {
 
@@ -72,7 +72,7 @@ namespace std {
 
 namespace {
 
-  using namespace units;
+  using namespace std::experimental::units;
 
   // class invariants
 
@@ -192,12 +192,12 @@ namespace {
   static_assert(std::is_same_v<decltype(quantity<kilometer, double>() - quantity<meter, int>()), quantity<meter, double>>);
   static_assert(std::is_same_v<decltype(quantity<meter, int>() * 1.0), quantity<meter, double>>);
   static_assert(std::is_same_v<decltype(1.0 * quantity<meter, int>()), quantity<meter, double>>);
-  static_assert(std::is_same_v<decltype(quantity<meter_per_second, int>() * units::quantity<second, int>()), quantity<units::meter, int>>);
-  static_assert(std::is_same_v<decltype(1 / units::quantity<second, int>()), quantity<hertz, int>>);
+  static_assert(std::is_same_v<decltype(quantity<meter_per_second, int>() * quantity<second, int>()), quantity<meter, int>>);
+  static_assert(std::is_same_v<decltype(1 / quantity<second, int>()), quantity<hertz, int>>);
   static_assert(std::is_same_v<decltype(quantity<meter, int>() / 1.0), quantity<meter, double>>);
   static_assert(std::is_same_v<decltype(quantity<meter, int>() / quantity<meter, double>()), double>);
   static_assert(std::is_same_v<decltype(quantity<kilometer, int>() / quantity<meter, double>()), double>);
-  static_assert(std::is_same_v<decltype(quantity<meter, int>() / units::quantity<second, int>()), quantity<meter_per_second, int>>);
+  static_assert(std::is_same_v<decltype(quantity<meter, int>() / quantity<second, int>()), quantity<meter_per_second, int>>);
   static_assert(std::is_same_v<decltype(quantity<meter, int>() % short(1)), quantity<meter, int>>);
   static_assert(std::is_same_v<decltype(quantity<meter, int>() % quantity<meter, short>(1)), quantity<meter, int>>);
 
diff --git a/test/unit_test/test_tools.cpp b/test/unit_test/test_tools.cpp
index ee887fba..23899293 100644
--- a/test/unit_test/test_tools.cpp
+++ b/test/unit_test/test_tools.cpp
@@ -24,7 +24,7 @@
 
 namespace {
 
-  using namespace units;
+  using namespace std::experimental::units;
 
   template<Ratio R1, Ratio R2>
   inline constexpr bool same = R1::num == R2::num && R1::den == R2::den;
diff --git a/test/unit_test/test_type_list.cpp b/test/unit_test/test_type_list.cpp
index 67f6e55a..2c6cd240 100644
--- a/test/unit_test/test_type_list.cpp
+++ b/test/unit_test/test_type_list.cpp
@@ -25,7 +25,7 @@
 
 namespace {
 
-  using namespace units;
+  using namespace std::experimental::units;
 
   template<typename... Types>
   struct type_list;
diff --git a/test/unit_test/test_units.cpp b/test/unit_test/test_units.cpp
index 48dcee0b..06efeaf9 100644
--- a/test/unit_test/test_units.cpp
+++ b/test/unit_test/test_units.cpp
@@ -37,7 +37,7 @@
 
 namespace {
 
-  using namespace units;
+  using namespace std::experimental::units;
 
   /* ************** BASE DIMENSIONS **************** */
 
@@ -71,6 +71,7 @@ namespace {
   static_assert(1000 / 1_s == 1_kHz);
   static_assert(1 / 1_ms == 1_kHz);
   static_assert(3.2_GHz == 3'200'000'000_Hz);
+//  static_assert(10_Hz * 1_min == 600);
 
   // velocity
 
@@ -100,4 +101,14 @@ namespace {
   static_assert(10_km * 10_km == 100_sq_km);
   static_assert(1_sq_m == 10'000_sq_cm);
 
+
+
+  // amplitude spectral density
+
+//  struct dimension_amplitude_spectral_density : make_dimension_t<exp<dim_voltage, 1>, exp<dim_frequency, ratio(-1, 2)>> {};
+//  template<> struct downcasting_traits<downcast_from<dimension_amplitude_spectral_density>> : downcast_to<dimension_amplitude_spectral_density> {};
+//
+//  struct volt_per_sq_hertz : derived_unit<dimension_amplitude_spectral_density, meter, second> {};
+//  template<> struct downcasting_traits<downcast_from<meter_per_second>> : downcast_to<meter_per_second> {};
+
 }  // namespace
diff --git a/test_package/test_package.cpp b/test_package/test_package.cpp
index 89383669..ec61a335 100644
--- a/test_package/test_package.cpp
+++ b/test_package/test_package.cpp
@@ -23,10 +23,11 @@
 #include <units/velocity.h>
 #include <iostream>
 
-using namespace units::literals;
+namespace stde = std::experimental;
+using namespace stde::units::literals;
 
-template<units::Length D, units::Time T>
-constexpr units::Velocity avg_speed(D d, T t)
+template<stde::units::Length D, stde::units::Time T>
+constexpr stde::units::Velocity avg_speed(D d, T t)
 {
   return d / t;
 }