diff --git a/libavcodec/atrac3.c b/libavcodec/atrac3.c
index cd120e9f6a..6a8fae72d8 100644
--- a/libavcodec/atrac3.c
+++ b/libavcodec/atrac3.c
@@ -941,9 +941,11 @@ static av_cold int atrac3_decode_init(AVCodecContext *avctx)
 
     if (q->coding_mode == STEREO)
         av_log(avctx, AV_LOG_DEBUG, "Normal stereo detected.\n");
-    else if (q->coding_mode == JOINT_STEREO)
+    else if (q->coding_mode == JOINT_STEREO) {
+        if (avctx->channels != 2)
+            return AVERROR_INVALIDDATA;
         av_log(avctx, AV_LOG_DEBUG, "Joint stereo detected.\n");
-    else {
+    } else {
         av_log(avctx, AV_LOG_ERROR, "Unknown channel coding mode %x!\n",
                q->coding_mode);
         return AVERROR_INVALIDDATA;