diff --git a/2.3.md b/2.3.md
index 8065f08a..5fd49ed8 100644
--- a/2.3.md
+++ b/2.3.md
@@ -385,7 +385,7 @@ Go里面有一个不错的设计，就是回调函数，有点类似面向对象
 	}
 
 	//声明的函数类型在这个地方当做了一个参数
-	func filter(slice []int, f test_int) []int {
+	func filter(slice []int, f testInt) []int {
 		var result []int
 		for _, value := range slice {
 			if f(value) {