diff --git a/subprojects/gst-plugins-bad/gst/videoparsers/gsth264parse.c b/subprojects/gst-plugins-bad/gst/videoparsers/gsth264parse.c
index 4a05287c9e..23b0ce09ca 100644
--- a/subprojects/gst-plugins-bad/gst/videoparsers/gsth264parse.c
+++ b/subprojects/gst-plugins-bad/gst/videoparsers/gsth264parse.c
@@ -1132,6 +1132,10 @@ gst_h264_parse_process_nal (GstH264Parse * h264parse, GstH264NalUnit * nalu)
       h264parse->header = TRUE;
       break;
     case GST_H264_NAL_SEI:
+      /* expected state: got-sps */
+      if (!GST_H264_PARSE_STATE_VALID (h264parse, GST_H264_PARSE_STATE_GOT_SPS))
+        return FALSE;
+
       h264parse->header = TRUE;
       gst_h264_parse_process_sei (h264parse, nalu);
       /* mark SEI pos */