diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c
index f7558116d1..7a3331bc0c 100644
--- a/libavcodec/vc1.c
+++ b/libavcodec/vc1.c
@@ -1021,6 +1021,8 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
                 v->reffield          = get_bits1(gb);
                 v->ref_field_type[0] = v->reffield ^ !v->cur_field_type;
             }
+        } else {
+            v->numref = 0;
         }
         if (v->extended_mv)
             v->mvrange = get_unary(gb, 0, 3);