diff --git a/lisp/net/puny.el b/lisp/net/puny.el
index 50bde85..b8a7cac 100644
--- a/lisp/net/puny.el
+++ b/lisp/net/puny.el
@@ -150,10 +150,12 @@ puny-decode-digit
 (defun puny-decode-string-internal (string)
   (with-temp-buffer
     (insert string)
+    ;; The encoded chars are after the final dash, if any
     (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)))
+    (if (search-backward "-" (point-min) t)
+        (forward-char 1)
+      (goto-char (point-min)))
+    (let ((encoded (buffer-substring (point) (point-max)))
           (ic 0)
           (i 0)
           (bias puny-initial-bias)