1 files changed, 2 insertions, 2 deletions

diff --git a/src/doc.c b/src/doc.c
index 8d84c8e7c40..a22034ae9d2 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -166,7 +166,7 @@ string is passed through `substitute-command-keys'.")
       tem = XVECTOR (fun)->contents[COMPILED_DOC_STRING];
       if (STRINGP (tem))
         doc = tem;
-      else if (INTEGERP (tem) && XINT (tem) >= 0)
+      else if (NATNUMP (tem))
         doc = get_doc_string (XFASTINT (tem));
       else
         return Qnil;
@@ -189,7 +189,7 @@ subcommands.)");
           tem = Fcar (Fcdr (Fcdr (fun)));
           if (STRINGP (tem))
             doc = tem;
-          else if (INTEGERP (tem) && XINT (tem) >= 0)
+          else if (NATNUMP (tem))
             doc = get_doc_string (XFASTINT (tem));
           else
             return Qnil;