diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c
index ef12253271..defe3c4850 100644
--- a/libavcodec/alsdec.c
+++ b/libavcodec/alsdec.c
@@ -668,6 +668,11 @@ static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
             int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
                                                 2, sconf->max_order + 1));
             *bd->opt_order       = get_bits(gb, opt_order_length);
+            if (*bd->opt_order > sconf->max_order) {
+                *bd->opt_order = sconf->max_order;
+                av_log(avctx, AV_LOG_ERROR, "Predictor order too large!\n");
+                return AVERROR_INVALIDDATA;
+            }
         } else {
             *bd->opt_order = sconf->max_order;
         }