diff --git a/doc/040_backup.rst b/doc/040_backup.rst
index c34670d19..8b4f2011e 100644
--- a/doc/040_backup.rst
+++ b/doc/040_backup.rst
@@ -355,6 +355,15 @@ the exclude options are:
 
 Please see ``restic help backup`` for more specific information about each exclude option.
 
+.. note::
+
+   Excludes do not apply to backup sources that were explicitly passed to the `backup`
+   command. That is ``restic backup ~/work.txt`` will always backup the file ``~/work.txt``
+   independent of any excludes.
+
+   This only applies to the exact paths that were explicitly passed to the `backup` command.
+   Content inside a directory you back up is still filtered by the given excludes.
+
 Suppose you have a file called ``excludes.txt`` with the following content:
 
 ::