diff --git a/modules/buster-configuration.rst b/modules/buster-configuration.rst
index 828cf07..28babcd 100644
--- a/modules/buster-configuration.rst
+++ b/modules/buster-configuration.rst
@@ -411,7 +411,7 @@ Content/file resources
 
 ``file``:
     File to serve. When ``file`` is set, you can not set ``combine`` or
-    ``content``.
+    ``content``. The ``file`` path is relative to the ``rootPath``.
 
 
 Proxy resources