diff --git a/libavcodec/tiertexseqv.c b/libavcodec/tiertexseqv.c
index 06c5fd6b09..af39f74d7d 100644
--- a/libavcodec/tiertexseqv.c
+++ b/libavcodec/tiertexseqv.c
@@ -213,10 +213,15 @@ static int seqvideo_decode(SeqVideoContext *seq, const unsigned char *data, int
 static av_cold int seqvideo_decode_init(AVCodecContext *avctx)
 {
     SeqVideoContext *seq = avctx->priv_data;
+    int ret;
 
     seq->avctx = avctx;
     avctx->pix_fmt = AV_PIX_FMT_PAL8;
 
+    ret = ff_set_dimensions(avctx, 256, 128);
+    if (ret < 0)
+        return ret;
+
     seq->frame = av_frame_alloc();
     if (!seq->frame)
         return AVERROR(ENOMEM);