diff --git a/libavcodec/r210enc.c b/libavcodec/r210enc.c
index 10ae001915..87bb64bfb6 100644
--- a/libavcodec/r210enc.c
+++ b/libavcodec/r210enc.c
@@ -75,7 +75,6 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
         src_line += pic->linesize[0];
     }
 
-    pkt->size   = 4 * aligned_width * avctx->height;
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
     return 0;
diff --git a/libavcodec/y41penc.c b/libavcodec/y41penc.c
index 1b81a5243a..577712543e 100644
--- a/libavcodec/y41penc.c
+++ b/libavcodec/y41penc.c
@@ -80,7 +80,6 @@ static int y41p_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
         }
     }
 
-    pkt->size   = 1.5 * avctx->width * avctx->height;
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
     return 0;