diff --git a/libavcodec/wnv1.c b/libavcodec/wnv1.c
index cbf271afc6..4e5f3ba69a 100644
--- a/libavcodec/wnv1.c
+++ b/libavcodec/wnv1.c
@@ -68,7 +68,7 @@ static int decode_frame(AVCodecContext *avctx,
     int prev_y = 0, prev_u = 0, prev_v = 0;
     uint8_t *rbuf;
 
-    if (buf_size <= 8) {
+    if (buf_size < 8 + avctx->height * (avctx->width/2)/8) {
         av_log(avctx, AV_LOG_ERROR, "Packet size %d is too small\n", buf_size);
         return AVERROR_INVALIDDATA;
     }