diff --git a/packages/arb-token-bridge-ui/src/util/WithdrawalUtils.ts b/packages/arb-token-bridge-ui/src/util/WithdrawalUtils.ts
index 17bf6596b7..7d14ef12e6 100644
--- a/packages/arb-token-bridge-ui/src/util/WithdrawalUtils.ts
+++ b/packages/arb-token-bridge-ui/src/util/WithdrawalUtils.ts
@@ -150,8 +150,9 @@ export function getConfirmationTime(chainId: number) {
   if (fastWithdrawalActive) {
     confirmationTimeInSeconds = fastWithdrawalTime / 1000
   } else {
-    // the block time is always base chain's block time regardless of withdrawing from L3 to L2 or from L2 to L1
-    // and similarly, the confirm period blocks is always the number of blocks on the base chain
+    // Calculate confirmation period using block time from root chain:
+    // - Ethereum mainnet for Arbitrum chains
+    // - Parent chain for Base chains
     const blockNumberReferenceChainId = getBlockNumberReferenceChainIdByChainId(
       { chainId }
     )