diff --git a/bundle/bundle--lisp.el b/bundle/bundle--lisp.el
index 5424b25c..e041e4d2 100644
--- a/bundle/bundle--lisp.el
+++ b/bundle/bundle--lisp.el
@@ -8,7 +8,7 @@
 Uses `mk/hyperspec-dir-locations' to find the directory."
   (let ((dir (seq-find 'file-directory-p mk/hyperspec-dir-locations)))
     (if dir
-        (concat "file://" (and (eq system-type 'windows-nt) "/") dir)
+        (concat "file://" (and (eq system-type 'windows-nt) "/") (expand-file-name dir))
       nil)))
 
 (setq common-lisp-hyperspec-root (mk/hyperspec-dir))