diff --git a/u_packet_packer.go b/u_packet_packer.go
index d9856177..33715407 100644
--- a/u_packet_packer.go
+++ b/u_packet_packer.go
@@ -250,7 +250,7 @@ func (p *uPacketPacker) MarshalInitialPacketPayload(pl payload, v protocol.Versi
 		return nil, err
 	}
 
-	if p.uSpec.InitialPacketSpec.FrameBuilder == nil || len(p.uSpec.InitialPacketSpec.FrameBuilder.(QUICFrames)) == 0 {
+	if qf, ok := p.uSpec.InitialPacketSpec.FrameBuilder.(QUICFrames); p.uSpec.InitialPacketSpec.FrameBuilder == nil || ok && len(qf) == 0 {
 		qfs := QUICFrames{}
 		for _, frame := range qchframes {
 			if cryptoFrame, ok := frame.(*clienthellod.CRYPTO); ok {
diff --git a/u_parrot_test.go b/u_parrot_test.go
new file mode 100644
index 00000000..8e4071cc
--- /dev/null
+++ b/u_parrot_test.go
@@ -0,0 +1,38 @@
+package quic
+
+import (
+	"context"
+	"net"
+	"testing"
+	"time"
+
+	tls "github.com/refraction-networking/utls"
+)
+
+func testDialPanic(t *testing.T, id QUICID) {
+
+	quicSpec, err := QUICID2Spec(id)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	pktConn, err := net.ListenUDP("udp", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	tr := &UTransport{Transport: &Transport{Conn: pktConn}, QUICSpec: &quicSpec}
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	tr.Dial(ctx, &net.UDPAddr{IP: net.IP{127, 0, 0, 1}, Port: 1234}, &tls.Config{}, &Config{})
+
+}
+
+func TestDialPanic(t *testing.T) {
+
+	for _, s := range []QUICID{QUICChrome_115, QUICFirefox_116} {
+		testDialPanic(t, s)
+	}
+
+}