diff --git a/av1/decoder/obu.c b/av1/decoder/obu.c
index 37de404..897a41e 100644
--- a/av1/decoder/obu.c
+++ b/av1/decoder/obu.c
@@ -836,6 +836,10 @@
         pbi->frame_header_size = (size_t)frame_header_size;
 
         if (cm->show_existing_frame) {
+          if (obu_header.type == OBU_FRAME) {
+            cm->error.error_code = AOM_CODEC_UNSUP_BITSTREAM;
+            return -1;
+          }
           frame_decoding_finished = 1;
           pbi->seen_frame_header = 0;
           break;