diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index 7dd3b005fe..3ccb89475e 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -878,6 +878,8 @@ static int amf_skip_tag(AVIOContext *pb, AMFDataType type, int depth)
         parse_name = 0;
     case AMF_DATA_TYPE_MIXEDARRAY:
         nb = avio_rb32(pb);
+        if (nb < 0)
+            return AVERROR_INVALIDDATA;
     case AMF_DATA_TYPE_OBJECT:
         while(!pb->eof_reached && (nb-- > 0 || type != AMF_DATA_TYPE_ARRAY)) {
             if (parse_name) {