diff --git a/documentation/ref-manual/ref-variables.xml b/documentation/ref-manual/ref-variables.xml
index a5d5ea2ab9..34083ac1ba 100644
--- a/documentation/ref-manual/ref-variables.xml
+++ b/documentation/ref-manual/ref-variables.xml
@@ -1987,8 +1987,12 @@ Core layer for images cannot be removed
                     You can specify shell commands and, if necessary, the path
                     to the root filesystem image:
                     <literallayout class='monospaced'>
-     ROOTFS_POSTPROCESS_COMMAND += "${IMAGE_ROOTFS}&lt;shell_command&gt;; ... "
+     IMAGE_POSTPROCESS_COMMAND += "&lt;shell_command&gt;; ... "
                     </literallayout>
+                    If you need to pass the path to the root filesystem within
+                    the command, you can use
+                    <filename>${IMAGE_ROOTFS}</filename>, which points to
+                    the root filesystem image.
                 </para>
             </glossdef>
         </glossentry>