diff --git a/document.md b/document.md
index ba72ff8..9c2f52c 100644
--- a/document.md
+++ b/document.md
@@ -50,7 +50,7 @@ may be mutated; the generator remembers the old cdr.
 ## Examples
 
 ```
-> (generator->list (floyd-generator '((1 2 3 4) '(a b c d) '(x y z))))
+> (generator->list (floyd-generator '((1 2 3 4) (a b c d) (x y z))))
 ((1 a x)
  (2 b y)
  (3 c z))