diff --git a/libavformat/ipmovie.c b/libavformat/ipmovie.c
index 676363b628..368c05922d 100644
--- a/libavformat/ipmovie.c
+++ b/libavformat/ipmovie.c
@@ -376,7 +376,7 @@ static int process_ipmovie_chunk(IPMVEContext *s, AVIOContext *pb,
 
         case OPCODE_INIT_VIDEO_BUFFERS:
             av_dlog(NULL, "initialize video buffers\n");
-            if ((opcode_version > 2) || (opcode_size > 8)) {
+            if ((opcode_version > 2) || (opcode_size > 8) || opcode_size < 4) {
                 av_dlog(NULL, "bad init_video_buffers opcode\n");
                 chunk_type = CHUNK_BAD;
                 break;