diff --git a/libavcodec/mpegpicture.c b/libavcodec/mpegpicture.c
index cb3ebcf7e7..681ccc2b82 100644
--- a/libavcodec/mpegpicture.c
+++ b/libavcodec/mpegpicture.c
@@ -334,7 +334,7 @@ void ff_mpeg_unref_picture(AVCodecContext *avctx, Picture *pic)
     memset((uint8_t*)pic + off, 0, sizeof(*pic) - off);
 }
 
-int ff_update_picture_tables(Picture *dst, Picture *src)
+int ff_update_picture_tables(Picture *dst, const Picture *src)
 {
     int i, ret;
 
diff --git a/libavcodec/mpegpicture.h b/libavcodec/mpegpicture.h
index c79693caba..0671bbae8e 100644
--- a/libavcodec/mpegpicture.h
+++ b/libavcodec/mpegpicture.h
@@ -109,7 +109,7 @@ int ff_mpeg_ref_picture(AVCodecContext *avctx, Picture *dst, Picture *src);
 void ff_mpeg_unref_picture(AVCodecContext *avctx, Picture *picture);
 
 void ff_mpv_picture_free(AVCodecContext *avctx, Picture *pic);
-int ff_update_picture_tables(Picture *dst, Picture *src);
+int ff_update_picture_tables(Picture *dst, const Picture *src);
 
 int ff_find_unused_picture(AVCodecContext *avctx, Picture *picture, int shared);