diff --git a/problems/0019.删除链表的倒数第N个节点.md b/problems/0019.删除链表的倒数第N个节点.md
index e05b9d03..188c4c57 100644
--- a/problems/0019.删除链表的倒数第N个节点.md
+++ b/problems/0019.删除链表的倒数第N个节点.md
@@ -173,8 +173,7 @@ var removeNthFromEnd = function(head, n) {
     let ret = new ListNode(0, head),
         slow = fast = ret;
     while(n--) fast = fast.next;
-    if(!fast) return ret.next;
-    while (fast.next) {
+    while (fast.next !== null) {
         fast = fast.next; 
         slow = slow.next
     };