diff --git a/src/ffmpeg.c b/src/ffmpeg.c
index 988d662..451d3da 100644
--- a/src/ffmpeg.c
+++ b/src/ffmpeg.c
@@ -1495,11 +1495,11 @@ int ffmpeg_put_image(struct ffmpeg *ffmpeg, struct image_data *img_data, const s
             ffmpeg->gop_cnt ++;
             if (ffmpeg->gop_cnt == ffmpeg->ctx_codec->gop_size ) {
                 ffmpeg->picture->pict_type = AV_PICTURE_TYPE_I;
-                ffmpeg->picture->key_frame = 1;
+                ffmpeg->picture->flags |= AV_FRAME_FLAG_KEY;
                 ffmpeg->gop_cnt = 0;
             } else {
                 ffmpeg->picture->pict_type = AV_PICTURE_TYPE_P;
-                ffmpeg->picture->key_frame = 0;
+                ffmpeg->picture->flags &= ~AV_FRAME_FLAG_KEY;
             }
 
             /* A return code of -2 is thrown by the put_frame