diff --git a/libavcodec/mpegaudiodec.c b/libavcodec/mpegaudiodec.c
index 6ed124b5f1ca92f9483fd93a18ee074ab0f9912d..0ab87e1a966ac75cae72bf19fab3a7a46dfd9975 100644
--- a/libavcodec/mpegaudiodec.c
+++ b/libavcodec/mpegaudiodec.c
@@ -1533,7 +1533,7 @@ static int mp_decode_layer3(MPADecodeContext *s)
             huffman_decode(s, g, exponents, bits_pos + g->part2_3_length);
         } /* ch */
 
-        if (s->nb_channels == 2)
+        if (s->mode == MPA_JSTEREO)
             compute_stereo(s, &s->granules[0][gr], &s->granules[1][gr]);
 
         for (ch = 0; ch < s->nb_channels; ch++) {