diff --git a/scripts/update_payload/common.py b/scripts/update_payload/common.py
index 9d008a9..38d949b 100644
--- a/scripts/update_payload/common.py
+++ b/scripts/update_payload/common.py
@@ -21,6 +21,9 @@
     '\x00\x04\x20'
 )
 
+CHROMEOS_MAJOR_PAYLOAD_VERSION = 1
+BRILLO_MAJOR_PAYLOAD_VERSION = 2
+
 INPLACE_MINOR_PAYLOAD_VERSION = 1
 SOURCE_MINOR_PAYLOAD_VERSION = 2