diff --git a/.emacs.d/lisp/main.el b/.emacs.d/lisp/main.el
index c12ead8e..22132be3 100644
--- a/.emacs.d/lisp/main.el
+++ b/.emacs.d/lisp/main.el
@@ -147,7 +147,22 @@
  ;; "s-w" 'other-window
  "s-c" 'delete-window)
 
+;; REVIEW: If xdg-open is not found, set Emacs URL browser to the environment browser,
+;; or w3m if BROWSER is not set.
+;; See https://debbugs.gnu.org/cgi/bugreport.cgi?bug=18986.
+;; In Emacs 26, the BROWSER variable is still not checked.
 (require 'browse-url)
+(setq browse-url-generic-program (or
+                                  (executable-find (or (getenv "BROWSER") ""))
+                                  (when (executable-find "xdg-mime")
+                                    (let ((desktop-browser (ambrevar/call-process-to-string "xdg-mime" "query" "default" "text/html")))
+                                      (substring desktop-browser 0 (string-match "\\.desktop" desktop-browser))))
+                                  (executable-find browse-url-mozilla-program)
+                                  (executable-find browse-url-firefox-program)
+                                  (executable-find browse-url-chromium-program)
+                                  (executable-find browse-url-kde-program)
+                                  (executable-find browse-url-conkeror-program)
+                                  (executable-find browse-url-chrome-program)))
 (setq browse-url-browser-function '(;; TODO: Display hyperspec in other window.
                                     ("http://www.lispworks.com/reference/HyperSpec/.*" . eww-browse-url)
                                     ("file:///.*HyperSpec.*" . eww-browse-url)