diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 7d5af9b877..cb32f0e300 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -3795,12 +3795,10 @@ static int mpeg4_update_thread_context(AVCodecContext *dst,
     memcpy(s->sprite_shift, s1->sprite_shift, sizeof(s1->sprite_shift));
     memcpy(s->sprite_traj,  s1->sprite_traj,  sizeof(s1->sprite_traj));
 
-    ret = av_buffer_replace(&s->bitstream_buffer, s1->bitstream_buffer);
-
     if (!init && s1->xvid_build >= 0)
         ff_xvid_idct_init(&s->m.idsp, dst);
 
-    return 0;
+    return av_buffer_replace(&s->bitstream_buffer, s1->bitstream_buffer);
 }
 
 static int mpeg4_update_thread_context_for_user(AVCodecContext *dst,