diff --git a/libavformat/mov.c b/libavformat/mov.c
index 5852355285..697b6908d1 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -5518,6 +5518,10 @@ static int mov_read_st3d(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         av_log(c->fc, AV_LOG_ERROR, "Empty stereoscopic video box\n");
         return AVERROR_INVALIDDATA;
     }
+
+    if (sc->stereo3d)
+        return AVERROR_INVALIDDATA;
+
     avio_skip(pb, 4); /* version + flags */
 
     mode = avio_r8(pb);