diff --git a/private/radix-tree.rkt b/private/radix-tree.rkt
index 2078a37..2fef0f7 100644
--- a/private/radix-tree.rkt
+++ b/private/radix-tree.rkt
@@ -135,7 +135,7 @@
 ;; Debug print function that dumps the tree to current-output-port in a vaguely human-readable
 ;; format
 (define (rt-dump node [prefix ""])
-  (displayln (format "~a node ~a" prefix (rt-node-data node)))
+  (displayln (format "~a node ~s" prefix (rt-node-data node)))
   (define edge0 (rt-node-edge0 node))
   (define edge1 (rt-node-edge1 node))
   (when edge0
@@ -155,11 +155,14 @@
     (lambda (_) x)
     (lambda () x)))
 ; (test-insert! "0001")
+; (test-insert! "")
+; (rt-dump test)
+; (test-insert! "0001")
 ; (test-insert! "000")
 ; (test-insert! "0")
 ; (rt-dump test)
 ; (rt-partial-iterate test (str->bl "0001"))
-; (rt-lookup test (str->bl "0001") (lambda () (error "bad")))
+; (rt-lookup test (str->bl "0000") (lambda () (error "bad")))
 
 ; (test-insert! "0001")
 ; (test-insert! "1000")