diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 8436032b18..a3f8db294c 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -2776,7 +2776,8 @@ static int decode_slice_header(H264Context *h, H264Context *h0)
                      || s->avctx->bits_per_raw_sample != h->sps.bit_depth_luma
                      || h->cur_chroma_format_idc != h->sps.chroma_format_idc
                      || av_cmp_q(h->sps.sar, s->avctx->sample_aspect_ratio)));
-
+    if (h0->s.avctx->pix_fmt != get_pixel_format(h0))
+        must_reinit = 1;
 
     s->mb_width  = h->sps.mb_width;
     s->mb_height = h->sps.mb_height * (2 - h->sps.frame_mbs_only_flag);