diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 6c097075d4..25dbf6cb3e 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -354,13 +354,13 @@ int ff_h264_update_thread_context(AVCodecContext *dst,
         h->ps.pps_ref = av_buffer_ref(h1->ps.pps_ref);
         if (!h->ps.pps_ref)
             return AVERROR(ENOMEM);
-        h->ps.pps = h->ps.pps_ref->data;
+        h->ps.pps = (const PPS*)h->ps.pps_ref->data;
     }
     if (h1->ps.sps_ref) {
         h->ps.sps_ref = av_buffer_ref(h1->ps.sps_ref);
         if (!h->ps.sps_ref)
             return AVERROR(ENOMEM);
-        h->ps.sps = h->ps.sps_ref->data;
+        h->ps.sps = (SPS*)h->ps.sps_ref->data;
     }
 
     if (need_reinit || !inited) {