diff --git a/problems/0376.摆动序列.md b/problems/0376.摆动序列.md
index 23348bd0..82b67451 100644
--- a/problems/0376.摆动序列.md
+++ b/problems/0376.摆动序列.md
@@ -177,7 +177,7 @@ var wiggleMaxLength = function(nums) {
     let result = 1
     let preDiff = 0
     let curDiff = 0
-    for(let i = 0; i <= nums.length; i++) {
+    for(let i = 0; i < nums.length - 1; i++) {
         curDiff = nums[i + 1] - nums[i]
         if((curDiff > 0 && preDiff <= 0) || (curDiff < 0 && preDiff >= 0)) {
             result++