diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index f8ad8de3b1..bd66de6ca2 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -1102,6 +1102,12 @@ 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:`CFLAGS`
       Specifies the flags to pass to the C compiler. This variable is
       exported to an environment variable and thus made visible to the