diff --git a/main.rkt b/main.rkt
index 91e335e..b07b2f3 100644
--- a/main.rkt
+++ b/main.rkt
@@ -51,6 +51,7 @@
         [(boolean? v) (if v "true" "false")]
         [(null? v) "[]"]
         [(list? v) (string-append "[" (string-join (map js-datum v) ", ") "]")]
+        [(pair? v) (js-datum (list (car v) (cdr v)))]
         [else (error 'js-datum "unsupported datum: ~e" v)]))
 
 (define (js-stmt s)