diff --git a/le-scheme.el b/le-scheme.el
index 667e2465..24bc9d5b 100644
--- a/le-scheme.el
+++ b/le-scheme.el
@@ -45,8 +45,10 @@
           (run-geiser geiser-impl--implementation)
         (call-interactively 'run-geiser))
       (geiser-mode 1)))
-  (when (and (not (member (geiser-racket--language) '(plait)))
-             (string-match "(\\(?:define\\|set!\\|struct\\)[ (]+\\(\\(?:\\w\\|\\s_\\)+\\)" str))
+  (when (and
+         (boundp 'geiser-racket--language)
+         (not (member (geiser-racket--language) '(plait)))
+         (string-match "(\\(?:define\\|set!\\|struct\\)[ (]+\\(\\(?:\\w\\|\\s_\\)+\\)" str))
     (let ((name (match-string 1 str)))
       (setq str (format "(begin %s %s)" str name))))
   (with-current-buffer (geiser-repl--buffer-name geiser-impl--implementation)