diff --git a/vorbis/decode.go b/vorbis/decode.go
index cb0c5dc..2f25108 100644
--- a/vorbis/decode.go
+++ b/vorbis/decode.go
@@ -67,14 +67,20 @@ func (d *decoder) Stream(samples [][2]float64) (n int, ok bool) {
 		leftChannelIndex = 0
 		rightChannelIndex = 0
 	case 2:
+		fallthrough
 	case 4:
 		leftChannelIndex = 0
 		rightChannelIndex = 1
 	case 3:
+		fallthrough
 	case 5:
+		fallthrough
 	case 6:
+		fallthrough
 	case 7:
+		fallthrough
 	case 8:
+		fallthrough
 	default:
 		leftChannelIndex = 0
 		rightChannelIndex = 2