diff --git a/docs/user-guide.rst b/docs/user-guide.rst
index 1b90f29..79d660d 100644
--- a/docs/user-guide.rst
+++ b/docs/user-guide.rst
@@ -322,8 +322,9 @@
    details.
 
 -  ``ENABLE_AMU``: Boolean option to enable Activity Monitor Unit extensions.
-   Currently this option only applies for platforms that include a v8.2 processor
-   with AMU implemented. Default is 0.
+   This is an optional architectural feature available on v8.4 onwards. Some
+   v8.2 implementations also implement an AMU and this option can be used to
+   enable this feature on those systems as well. Default is 0.
 
 -  ``ENABLE_ASSERTIONS``: This option controls whether or not calls to ``assert()``
    are compiled out. For debug builds, this option defaults to 1, and calls to