diff --git a/sex-mode.el b/sex-mode.el
index c574bf6..7a5932a 100644
--- a/sex-mode.el
+++ b/sex-mode.el
@@ -30,6 +30,8 @@ All commands in `lisp-mode-shared-map' are inherited by this map.")
      (list (concat "("
                    (regexp-opt '("chicken-import"
                                  "chicken-load"
+                                 "define"
+                                 "define-syntax"
                                  "extern"
                                  "include"
                                  "fn"