1 files changed, 2 insertions, 1 deletions

diff --git a/src/data.c b/src/data.c
index c70e3219eac..10d6a1e9eb5 100644
--- a/src/data.c
+++ b/src/data.c
@@ -275,7 +275,8 @@ DEFUN ("atom", Fatom, Satom, 1, 1, 0,
 }
 
 DEFUN ("listp", Flistp, Slistp, 1, 1, 0,
-       doc: /* Return t if OBJECT is a list.  This includes nil.  */)
+       doc: /* Return t if OBJECT is a list, that is, a cons cell or nil.
+Otherwise, return nil.  */)
      (object)
      Lisp_Object object;
 {