diff --git a/tun/tun.go b/tun/tun.go
index a1c1f91..252140e 100644
--- a/tun/tun.go
+++ b/tun/tun.go
@@ -49,7 +49,7 @@ func (t *SourceSink) Source() (proxy.Packet, error) {
 		return nil, io.EOF
 	}
 
-	return proxy.SimplePacket(buf[4:read+4]), nil
+	return proxy.SimplePacket(buf[4 : read+4]), nil
 }
 
 var good, bad float64