diff --git a/docs/use_cases/extensions.rst b/docs/use_cases/extensions.rst
index fd9db565..fd2281a8 100644
--- a/docs/use_cases/extensions.rst
+++ b/docs/use_cases/extensions.rst
@@ -258,14 +258,14 @@ Even though the base dimension of ``si::fps`` is defined in terms of
 ``si::metre`` foot is preserved as the base unit of length in both systems::
 
     constexpr auto fps_yard = fps::length<fps::yard>(1.);
-    constexpr auto fps_area = quantity_cast<unknown_coherent_unit>(fps_yard * fps_yard);
-    std::cout << fps_yard << "\n";     // 1 yd
-    std::cout << fps_area << "\n";     // 9 ft²
+    constexpr auto fps_area = fps_yard * fps_yard;
+    std::cout << fps_yard << "\n";                                                               // 1 yd
+    std::cout << quantity_cast<decltype(fps_area)::dimension::coherent_unit>(fps_area) << "\n";  // 9 ft²
 
     constexpr auto si_fps_yard = si::fps::length<si::fps::yard>(1.);
-    constexpr auto si_fps_area = quantity_cast<unknown_coherent_unit>(si_fps_yard * si_fps_yard);
-    std::cout << si_fps_yard << "\n";  // 1 yd
-    std::cout << si_fps_area << "\n";  // 9 ft²
+    constexpr auto si_fps_area = si_fps_yard * si_fps_yard;
+    std::cout << si_fps_yard << "\n";                                                                  // 1 yd
+    std::cout << quantity_cast<decltype(si_fps_area)::dimension::coherent_unit>(si_fps_area) << "\n";  // 9 ft²
 
 In most cases we want conversions between systems and that is why nearly all
 systems provided with this library are implemented in terms on the :term:`SI`
diff --git a/docs/use_cases/unknown_dimensions.rst b/docs/use_cases/unknown_dimensions.rst
index d23e227f..f3e3140d 100644
--- a/docs/use_cases/unknown_dimensions.rst
+++ b/docs/use_cases/unknown_dimensions.rst
@@ -52,7 +52,7 @@ dimensions used in the division operation:
     static_assert(std::is_same_v<decltype(result)::dimension,
                                  unknown_dimension<exponent<dim_length, 1>, exponent<dim_time, -1>>>);
     static_assert(std::is_same_v<decltype(result)::unit,
-                                 scaled_unit<ratio(1, 36, 1), unknown_coherent_unit>>);
+                                 scaled_unit<ratio(1, 36, 1), unknown_coherent_unit<exponent<dim_length, 1>, exponent<dim_time, -1>>>>>);
 
 .. important::
 
@@ -81,7 +81,7 @@ this particular unknown derived dimension.
 In case we would like to print the result in terms of base units we can simply do the
 following::
 
-    auto s = quantity_cast<unknown_coherent_unit>(result);
+    auto s = quantity_cast<decltype(result)::dimension::coherent_unit>(result);
     std::cout << "Speed: " << s << '\n';  // prints 'Speed: 20 m/s'
 
 .. seealso::