diff --git a/transport/internet/kcp/config.go b/transport/internet/kcp/config.go
index a7607cfb..8eeafa0d 100644
--- a/transport/internet/kcp/config.go
+++ b/transport/internet/kcp/config.go
@@ -6,7 +6,7 @@ type Config struct {
 	UplinkCapacity   uint32
 	DownlinkCapacity uint32
 	Congestion       bool
-	WriteBuffer      int
+	WriteBuffer      uint32
 }
 
 func (this *Config) Apply() {