diff --git a/docs/kotlin.md b/docs/kotlin.md
index ae09dbf..c0fd3d0 100644
--- a/docs/kotlin.md
+++ b/docs/kotlin.md
@@ -523,7 +523,7 @@ fun main() {
 ### 默认参数
 
 ```kotlin
-fun favoriteLanguage(name, language = "Kotlin") {
+fun favoriteLanguage(name: String, language: String = "Kotlin") {
   println("Hello, $name. Your favorite programming language is $language")  
 }