diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index f2ca9b33c6..7d9da5c106 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -931,7 +931,7 @@ int ff_mpeg_update_thread_context(AVCodecContext *dst,
 #define UPDATE_PICTURE(pic)\
 do {\
     ff_mpeg_unref_picture(s, &s->pic);\
-    if (s1->pic.f->buf[0])\
+    if (s1->pic.f && s1->pic.f->buf[0])\
         ret = ff_mpeg_ref_picture(s, &s->pic, &s1->pic);\
     else\
         ret = update_picture_tables(&s->pic, &s1->pic);\