diff --git a/libavcodec/mpc8.c b/libavcodec/mpc8.c
index c37cd50497..652e824843 100644
--- a/libavcodec/mpc8.c
+++ b/libavcodec/mpc8.c
@@ -140,7 +140,8 @@ static av_cold int mpc8_decode_init(AVCodecContext * avctx)
     c->frames = 1 << (get_bits(&gb, 3) * 2);
 
     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
-    avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
+    avctx->channel_layout = (channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
+    avctx->channels = channels;
 
     if(vlc_initialized) return 0;
     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");