diff --git a/libavcodec/on2avc.c b/libavcodec/on2avc.c
index deaa2b4c04..c00339f7b0 100644
--- a/libavcodec/on2avc.c
+++ b/libavcodec/on2avc.c
@@ -918,6 +918,10 @@ static av_cold int on2avc_decode_init(AVCodecContext *avctx)
         av_log(avctx, AV_LOG_ERROR, "0x500 version should be mono\n");
         return AVERROR_INVALIDDATA;
     }
+    if (avctx->channels > 2) {
+        av_log(avctx, AV_LOG_ERROR, "Only 1 or 2 channels are supported.\n");
+        return AVERROR(EINVAL);
+    }
     if (avctx->channels == 2)
         av_log(avctx, AV_LOG_WARNING,
                "Stereo mode support is not good, patch is welcome\n");