diff --git a/lisp/ob-awk.el b/lisp/ob-awk.el
index ff5a9671c..1ba0a3569 100644
--- a/lisp/ob-awk.el
+++ b/lisp/ob-awk.el
@@ -48,7 +48,7 @@
   "Expand BODY according to PARAMS, return the expanded body."
   (dolist (pair (mapcar #'cdr (org-babel-get-header params :var)))
     (setf body (replace-regexp-in-string
-                (regexp-quote (concat "$" (car pair))) (cdr pair) body)))
+                (regexp-quote (format "$%s" (car pair))) (cdr pair) body)))
   body)
 
 (defun org-babel-execute:awk (body params)