diff --git a/libavcodec/avs.c b/libavcodec/avs.c
index d4e28372127dc4bab683230ce206d6afb26e0835..b8ee1e1ff29631da55226a0ba9da9e05889dbdcc 100644
--- a/libavcodec/avs.c
+++ b/libavcodec/avs.c
@@ -158,6 +158,7 @@ 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;
 }