diff --git a/lisp/net/puny.el b/lisp/net/puny.el
index c718d958be1..bdd59be070a 100644
--- a/lisp/net/puny.el
+++ b/lisp/net/puny.el
@@ -150,10 +150,12 @@ For instance \"xn--bcher-kva\" => \"bücher\"."
 (defun puny-decode-string-internal (string)
   (with-temp-buffer
     (insert string)
-    (goto-char (point-max))
-    (search-backward "-" nil (point-min))
-    ;; The encoded chars are after the final dash.
-    (let ((encoded (buffer-substring (1+ (point)) (point-max)))
+    ;; The encoded chars are after any final dash, else the whole string.
+    (let ((encoded (buffer-substring
+                    (if (search-backward "-" nil 'move)
+                        (1+ (point))
+                      (point))
+                    (point-max)))
           (ic 0)
           (i 0)
           (bias puny-initial-bias)