diff --git a/modules/lang/julia/autoload.el b/modules/lang/julia/autoload.el
index 7f9285db7..5d0d16641 100644
--- a/modules/lang/julia/autoload.el
+++ b/modules/lang/julia/autoload.el
@@ -1,5 +1,10 @@
 ;;; lang/julia/autoload.el -*- lexical-binding: t; -*-
 
+;; `ob-julia' needs this variable to be defined, but it's defined in
+;; `ess-custom', which won't be available if you're using :lang julia and not
+;; :lang ess.
+;;;###autoload (defvar inferior-julia-program-name (or (executable-find "julia-basic") "julia"))
+
 ;;;###autoload
 (defun +julia/open-repl ()
   "Run an inferior instance of `julia' inside Emacs."