diff --git a/transducers.lisp b/transducers.lisp
index 7a73062..df17a47 100644
--- a/transducers.lisp
+++ b/transducers.lisp
@@ -127,22 +127,19 @@
 
 (defmethod init ((it (eql 'list-builder)))
   (declare (optimize (speed 3)))
-  (coerce (vector nil nil)
-          '(simple-array list (2))))
+  (let ((it (list nil)))
+    (coerce (vector it it)
+            '(simple-array list (2)))))
 (defmethod stepper ((it (eql 'list-builder)))
   (lambda (acc a)
     (declare (optimize (speed 3))
              (type (simple-array list (2)) acc))
-    (if (elt acc 1)
-        (let* ((to-build (elt acc 1)))
-          (push a (cdr to-build))
-          (setf (elt acc 1) (cdr to-build)))
-        (let ((new (list a)))
-          (setf (elt acc 0) new
-                (elt acc 1) new)))
+    (let* ((to-build (elt acc 1)))
+      (push a (cdr to-build))
+      (setf (elt acc 1) (cdr to-build)))
     acc))
 (defmethod unwrap ((it (eql 'list-builder)) obj)
-  (elt obj 0))
+  (cdr (elt obj 0)))
 
 (defclass lazy-sequence ()
   ((%next :initarg :next :reader next)))