diff --git a/phobos.el b/phobos.el
index ffb11ab..6268609 100644
--- a/phobos.el
+++ b/phobos.el
@@ -38,7 +38,8 @@ or any other symbol part of a standard module, such as object.Exception.
 Phobos is the standard library for the D programming language. For more
 information on Phobos and the D programming language, see <https://dlang.org>."
   (interactive "MModule or symbol: ")
-  (shell-command (concat phobos-browser " " phobos-root "/"
-                         (string-replace "." "/" symbol) ".html")))
+  (shell-command (format "%s %s/%s.html"
+                         phobos-browser phobos-root
+                         (string-replace "." "/" symbol))))
 
 (provide 'phobos)