diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 4fef2f7338..12123cda0e 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -146,7 +146,8 @@ static void mpeg_er_decode_mb(void *opaque, int ref, int mv_dir, int mv_type,
     s->dest[1] = s->current_picture.f.data[1] + (s->mb_y * (16 >> s->chroma_y_shift) * s->uvlinesize) + s->mb_x * (16 >> s->chroma_x_shift);
     s->dest[2] = s->current_picture.f.data[2] + (s->mb_y * (16 >> s->chroma_y_shift) * s->uvlinesize) + s->mb_x * (16 >> s->chroma_x_shift);
 
-    assert(ref == 0);
+    if (ref)
+        av_log(s->avctx, AV_LOG_DEBUG, "Interlaced error concealment is not fully implemented\n");
     ff_MPV_decode_mb(s, s->block);
 }