diff --git a/src/bin/gs_guc/cluster_guc.conf b/src/bin/gs_guc/cluster_guc.conf
index dee2e5922b3649d3836c8cd07038e44471adddfb..e480e990f1258601997ad72034330f3694c3570c 100755
--- a/src/bin/gs_guc/cluster_guc.conf
+++ b/src/bin/gs_guc/cluster_guc.conf
@@ -903,6 +903,7 @@ ddb_log_backup_file_count|int|1,100|NULL|NULL|
 ddb_max_log_file_size|string|0,0|NULL|NULL|
 ddb_log_suppress_enable|int|0,1|NULL|NULL|
 ddb_election_timeout|int|1,600|NULL|NULL|
+upgrade_from|int|0,4294967295|NULL|For upgrading, specify which version we are upgrading from.|
 [cmagent]
 log_dir|string|0,0|NULL|NULL|
 log_file_size|int|0,2047|MB|NULL|