diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index d5f491087671..eea2188142f6 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -826,6 +826,8 @@ If no files are marked or a numeric prefix arg is given,
 the next ARG files are used.  Just \\[universal-argument] means the current file.
 The prompt mentions the file(s) or the marker, as appropriate.
 
+When executing, FILE-LIST is appended to the COMMAND string.
+
 If there is a `*' in COMMAND, surrounded by whitespace, this runs
 COMMAND just once with the entire file list substituted there.