diff --git a/op/ronin/mainnet/genesis.json b/op/ronin/mainnet/genesis.json
index db778703..2ec9ab6d 100644
--- a/op/ronin/mainnet/genesis.json
+++ b/op/ronin/mainnet/genesis.json
@@ -27,6 +27,7 @@
     "holoceneTime": 0,
     "isthmusTime": 0,
     "jovianTime": 0,
+    "karstTime": 1791388801,
     "terminalTotalDifficulty": 0,
     "depositContractAddress": "0x0000000000000000000000000000000000000000",
     "optimism": {
diff --git a/op/ronin/mainnet/rollup.json b/op/ronin/mainnet/rollup.json
index a029816b..8165e403 100644
--- a/op/ronin/mainnet/rollup.json
+++ b/op/ronin/mainnet/rollup.json
@@ -35,6 +35,7 @@
   "holocene_time": 0,
   "isthmus_time": 0,
   "jovian_time": 0,
+  "karst_time": 1791388801,
   "batch_inbox_address": "0x003a7a2d3129838adb01c8d9b7da62ac6ec27961",
   "deposit_contract_address": "0x652cd53ecf9466e5fb00d0e11d6cbf6469a56d77",
   "l1_system_config_address": "0xc4f4f908c36c8119f1fbd52cebbdb30c6f2a23c1",
diff --git a/op/ronin/saigon/genesis.json b/op/ronin/saigon/genesis.json
index 88c015f8..d0548559 100644
--- a/op/ronin/saigon/genesis.json
+++ b/op/ronin/saigon/genesis.json
@@ -35,6 +35,7 @@
     "holoceneTime": 0,
     "isthmusTime": 0,
     "jovianTime": 0,
+    "karstTime": 1788364801,
     "conduit": {
       "stateOverrideFork0": {
         "time": 1771891200,
diff --git a/op/ronin/saigon/rollup.json b/op/ronin/saigon/rollup.json
index c48271ff..a4541c37 100644
--- a/op/ronin/saigon/rollup.json
+++ b/op/ronin/saigon/rollup.json
@@ -35,6 +35,7 @@
   "holocene_time": 0,
   "isthmus_time": 0,
   "jovian_time": 0,
+  "karst_time": 1788364801,
   "batch_inbox_address": "0x00a4d9a78f8d80ff95912a6ace8e870df35bd900",
   "deposit_contract_address": "0xe8776570681541d5d3fc1f27af7628a775626244",
   "l1_system_config_address": "0x29f680c13e0d88fc084e2a0462d69978992a1a6e",