diff --git a/modules/stream_out/transcode.c b/modules/stream_out/transcode.c
index 9555e661d6ec947d9cca29d9aca742e618db6bef..dc8b09bf4f3f734e80901ab9993894f4da8d0096 100644
--- a/modules/stream_out/transcode.c
+++ b/modules/stream_out/transcode.c
@@ -1608,6 +1608,11 @@ static int transcode_video_process( sout_stream_t *p_stream,
             else
                 p_fmt = &id->p_decoder->fmt_out.video;
 
+            /* FIXME (shouldn't have to be done here) */
+            p_fmt->i_sar_num = p_fmt->i_aspect *
+                p_fmt->i_height / p_fmt->i_width;
+            p_fmt->i_sar_den = VOUT_ASPECT_FACTOR;
+
             spu_RenderSubpictures( p_sys->p_spu, p_fmt, p_pic, p_pic, p_subpic,
                                    i_scale_width, i_scale_height );
         }