diff --git a/libavformat/matroska.c b/libavformat/matroska.c
index c592fb0ce3..f3e1be796d 100644
--- a/libavformat/matroska.c
+++ b/libavformat/matroska.c
@@ -150,26 +150,13 @@ const char * const ff_matroska_video_stereo_plane[MATROSKA_VIDEO_STEREO_PLANE_CO
 
 int ff_mkv_stereo3d_conv(AVStream *st, MatroskaVideoStereoModeType stereo_mode)
 {
-    AVPacketSideData *sd, *tmp;
     AVStereo3D *stereo;
+    int ret;
 
     stereo = av_stereo3d_alloc();
     if (!stereo)
         return AVERROR(ENOMEM);
 
-    tmp = av_realloc_array(st->side_data, st->nb_side_data + 1, sizeof(*tmp));
-    if (!tmp) {
-        av_freep(&stereo);
-        return AVERROR(ENOMEM);
-    }
-    st->side_data = tmp;
-    st->nb_side_data++;
-
-    sd = &st->side_data[st->nb_side_data - 1];
-    sd->type = AV_PKT_DATA_STEREO3D;
-    sd->data = (uint8_t *)stereo;
-    sd->size = sizeof(*stereo);
-
     // note: the missing breaks are intentional
     switch (stereo_mode) {
     case MATROSKA_VIDEO_STEREOMODE_TYPE_MONO:
@@ -207,5 +194,12 @@ int ff_mkv_stereo3d_conv(AVStream *st, MatroskaVideoStereoModeType stereo_mode)
         break;
     }
 
+    ret = av_stream_add_side_data(st, AV_PKT_DATA_STEREO3D, (uint8_t *)stereo,
+                                  sizeof(*stereo));
+    if (ret < 0) {
+        av_freep(&stereo);
+        return ret;
+    }
+
     return 0;
 }