--- a/sertop/sertop.el
+++ b/sertop/sertop.el
@@ -37,7 +37,7 @@
                            (buffer-file-name))))
 
 (defvar sertop-executable-path
-  (or (expand-file-name "sertop.native" sertop--root)
+  (or (executable-find "sertop.native")
       (executable-find "sertop"))
   "Path to sertop.")