diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index e7ffe45d0f..d1662fcb6b 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -1908,7 +1908,8 @@ static int decode_slice_header(H264Context *h, H264Context *h0){
             h->prev_frame_num++;
             h->prev_frame_num %= 1<<h->sps.log2_max_frame_num;
             s->current_picture_ptr->frame_num= h->prev_frame_num;
-            ff_h264_execute_ref_pic_marking(h, NULL, 0);
+            ff_generate_sliding_window_mmcos(h);
+            ff_h264_execute_ref_pic_marking(h, h->mmco, h->mmco_index);
         }
 
         /* See if we have a decoded first field looking for a pair... */
diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
index 7caa4b0003..74eaaa8ada 100644
--- a/libavcodec/h264_refs.c
+++ b/libavcodec/h264_refs.c
@@ -478,6 +478,7 @@ void ff_generate_sliding_window_mmcos(H264Context *h) {
     MpegEncContext * const s = &h->s;
     assert(h->long_ref_count + h->short_ref_count <= h->sps.ref_frame_count);
 
+    h->mmco_index= 0;
     if(h->short_ref_count && h->long_ref_count + h->short_ref_count == h->sps.ref_frame_count &&
             !(FIELD_PICTURE && !s->first_field && s->current_picture_ptr->reference)) {
         h->mmco[0].opcode= MMCO_SHORT2UNUSED;