diff --git a/subprojects/gst-plugins-good/ext/adaptivedemux2/downloadhelper.h b/subprojects/gst-plugins-good/ext/adaptivedemux2/downloadhelper.h
index a5abdeba10..563e4ff9e4 100644
--- a/subprojects/gst-plugins-good/ext/adaptivedemux2/downloadhelper.h
+++ b/subprojects/gst-plugins-good/ext/adaptivedemux2/downloadhelper.h
@@ -32,6 +32,9 @@ typedef enum DownloadFlags DownloadFlags;
 
 #define HTTP_STATUS_IS_SUCCESSFUL(s) ((s) >= 200 && (s) < 300)
 
+/* RFC8673 recommended last-byte-pos value of 2^^53-1 */
+#define RFC8673_LAST_BYTE_POS (9007199254740991)
+
 enum DownloadFlags
 {
   DOWNLOAD_FLAG_NONE = 0,