diff --git a/build/params_mainnet.go b/build/params_mainnet.go
index 95ec348c1..c607bcdd0 100644
--- a/build/params_mainnet.go
+++ b/build/params_mainnet.go
@@ -95,8 +95,8 @@ const UpgradeLightningHeight = 2809800
 // 2023-05-18T13:00:00Z
 const UpgradeThunderHeight = UpgradeLightningHeight + 2880*21
 
-// ???????
-var UpgradeWatermelonHeight = abi.ChainEpoch(9999999999)
+// 2023-11-29T13:30:00Z
+var UpgradeWatermelonHeight = abi.ChainEpoch(3431940)
 
 // This fix upgrade only ran on calibrationnet
 const UpgradeWatermelonFixHeight = -1