diff --git a/ansi/rope.rkt b/ansi/rope.rkt
index 5ce0c08..778abeb 100644
--- a/ansi/rope.rkt
+++ b/ansi/rope.rkt
@@ -8,6 +8,7 @@
          strand-equal?
          strand-empty?
 
+         rope?
          empty-rope
          strand->rope
          string->rope