diff --git a/op/celo/mainnet/rollup.json b/op/celo/mainnet/rollup.json
index ff6bd239..345f5ce0 100644
--- a/op/celo/mainnet/rollup.json
+++ b/op/celo/mainnet/rollup.json
@@ -30,6 +30,8 @@
   "ecotone_time": 0,
   "fjord_time": 0,
   "granite_time": 0,
+  "holocene_time": 1752073200,
+  "isthmus_time": 1752073200,
   "batch_inbox_address": "0xff00000000000000000000000000000000042220",
   "deposit_contract_address": "0xc5c5d157928bdbd2acf6d0777626b6c75a9eaedc",
   "l1_system_config_address": "0x89e31965d844a309231b1f17759ccaf1b7c09861",