diff --git a/libavcodec/avs.c b/libavcodec/avs.c
index 3b29c853b4..e8a55fdddd 100644
--- a/libavcodec/avs.c
+++ b/libavcodec/avs.c
@@ -145,6 +145,7 @@ avs_decode_frame(AVCodecContext * avctx,
 static av_cold int avs_decode_init(AVCodecContext * avctx)
 {
     avctx->pix_fmt = PIX_FMT_PAL8;
+    avcodec_set_dimensions(avctx, 318, 198);
     return 0;
 }