diff --git a/oni-package.el b/oni-package.el
index e277b0e..0a283a8 100644
--- a/oni-package.el
+++ b/oni-package.el
@@ -114,5 +114,18 @@ DESCRIPTION is the text of the news item."
 
 (add-hook 'package-menu-mode-hook 'hl-line-mode)
 
+;; Set up a keybinding to open a package's URL
+
+(defun oni-package-open-url ()
+  (interactive nil package-menu-mode)
+  (let* ((pkg-desc (tabulated-list-get-id))
+         (url (map-elt (package-desc-extras pkg-desc) :url)))
+    (if url
+        (browse-url url)
+      (error "Package %s doesn't appear to have a url"
+             (package-desc-name pkg-desc)))))
+
+(define-key package-menu-mode-map (kbd "o") #'oni-package-open-url)
+
 (provide 'oni-package)
 ;;; oni-package.el ends here