diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index a67090308b..62417d045c 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -1463,6 +1463,12 @@ system and gives an overview of their function and contents.
       :term:`CCACHE_DISABLE` variable can be set to "1" in a recipe to disable
       `Ccache` support. This is useful when the recipe is known to not support it.
 
+   :term:`CCACHE_TOP_DIR`
+      When inheriting the :ref:`ref-classes-ccache` class, the
+      :term:`CCACHE_TOP_DIR` variable can be set to the location of where
+      `Ccache` stores its cache files. This directory can be shared between
+      builds.
+
    :term:`CCLD`
       The minimal command and arguments used to run the linker when the C
       compiler is being used as the linker.