diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 2be67536d0..70de4cfe48 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -6371,12 +6371,13 @@ static void filter_mb_edgech( H264Context *h, uint8_t *pix, int stride, int16_t
 
 static void filter_mb_fast( H264Context *h, int mb_x, int mb_y, uint8_t *img_y, uint8_t *img_cb, uint8_t *img_cr, unsigned int linesize, unsigned int uvlinesize) {
     MpegEncContext * const s = &h->s;
+    int mb_y_firstrow = s->picture_structure == PICT_BOTTOM_FIELD;
     int mb_xy, mb_type;
     int qp, qp0, qp1, qpc, qpc0, qpc1, qp_thresh;
 
     mb_xy = mb_x + mb_y*s->mb_stride;
 
-    if(mb_x==0 || mb_y==0 || !s->dsp.h264_loop_filter_strength || h->pps.chroma_qp_diff ||
+    if(mb_x==0 || mb_y==mb_y_firstrow || !s->dsp.h264_loop_filter_strength || h->pps.chroma_qp_diff ||
        (h->deblocking_filter == 2 && (h->slice_table[mb_xy] != h->slice_table[h->top_mb_xy] ||
                                       h->slice_table[mb_xy] != h->slice_table[mb_xy - 1]))) {
         filter_mb(h, mb_x, mb_y, img_y, img_cb, img_cr, linesize, uvlinesize);