diff --git a/docs/framework/units.rst b/docs/framework/units.rst
index 847caa66..ecded34a 100644
--- a/docs/framework/units.rst
+++ b/docs/framework/units.rst
@@ -146,7 +146,7 @@ where ``kilogram_metre_per_second`` is defined as::
     struct kilogram_metre_per_second : unit<kilogram_metre_per_second> {};
 
 However, the easiest way to define momentum is just to use the
-``si::speed`` derived dimension in the recipe:
+``si::dim_speed`` derived dimension in the recipe:
 
 .. code-block::
     :emphasize-lines: 3