diff --git a/contracts/oasys/deployments.go b/contracts/oasys/deployments.go
index 3f9acfc23..1393a023e 100644
--- a/contracts/oasys/deployments.go
+++ b/contracts/oasys/deployments.go
@@ -21,7 +21,7 @@ var deploymentSets = map[common.Hash]map[uint64]deploymentSet{
 		1529980: deploymentSet{deployments9},
 		1892000: deploymentSet{deployments10},
 		4089588: deploymentSet{deployments11},
-		9999998: deploymentSet{deployments12}, // TODO
+		5095900: deploymentSet{deployments12},
 	},
 	params.OasysTestnetGenesisHash: {
 		1:       deploymentSet{deployments0},
diff --git a/contracts/oasys/oasys_test.go b/contracts/oasys/oasys_test.go
index 70008f0c9..f3ee5e7b8 100644
--- a/contracts/oasys/oasys_test.go
+++ b/contracts/oasys/oasys_test.go
@@ -1152,7 +1152,7 @@ func TestDeploy(t *testing.T) {
 				{1529980, []deployFn{_deployments9}},
 				{1892000, []deployFn{_deployments10}},
 				{4089588, []deployFn{_deployments11}},
-				{9999998, []deployFn{_deployments12}},
+				{5095900, []deployFn{_deployments12}},
 			},
 		},
 		{
diff --git a/params/config.go b/params/config.go
index b6828e531..a57902dcb 100644
--- a/params/config.go
+++ b/params/config.go
@@ -626,7 +626,7 @@ func (c *ChainConfig) OasysFastFinalityEnabledBlock() *big.Int {
 		return nil
 	}
 	if c.ChainID.Cmp(OasysMainnetChainConfig.ChainID) == 0 {
-		return big.NewInt(9999999)
+		return big.NewInt(5095900) // Mon Nov 18 2024 17:00:00 GMT+0900
 	}
 	if c.ChainID.Cmp(OasysTestnetChainConfig.ChainID) == 0 {
 		return big.NewInt(4958700) // Thu Oct 31 2024 18:00:00 GMT+0900