diff --git a/outbound/hysteria.go b/outbound/hysteria.go
index 200820b9..d3875f0c 100644
--- a/outbound/hysteria.go
+++ b/outbound/hysteria.go
@@ -45,6 +45,7 @@ type Hysteria struct {
 }
 
 func NewHysteria(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.HysteriaOutboundOptions) (*Hysteria, error) {
+	options.UDPFragmentDefault = true
 	if options.TLS == nil || !options.TLS.Enabled {
 		return nil, C.ErrTLSRequired
 	}