diff --git a/ops-bedrock/devnet-up.sh b/ops-bedrock/devnet-up.sh
index 3e562cfc3f0c..f98db3c4a06d 100755
--- a/ops-bedrock/devnet-up.sh
+++ b/ops-bedrock/devnet-up.sh
@@ -58,9 +58,9 @@ function wait_up {
 mkdir -p ./.devnet
 
 if [ ! -f ./.devnet/rollup.json ]; then
-    GENESIS_TIMESTAMP=$(date +%s | xargs printf "0x%x")
+    L1_GENESIS_TIMESTAMP=$(date +%s | xargs printf "0x%x")
 else
-    GENESIS_TIMESTAMP=$(jq '.timestamp' < .devnet/genesis-l1.json)
+    L1_GENESIS_TIMESTAMP=$(jq '.timestamp' < .devnet/genesis-l1.json)
 fi
 
 # Regenerate the L1 genesis file if necessary. The existence of the genesis
@@ -69,7 +69,7 @@ if [ ! -f ./.devnet/genesis-l1.json ]; then
   echo "Regenerating L1 genesis."
   (
     cd $CONTRACTS_BEDROCK
-    L2OO_STARTING_BLOCK_TIMESTAMP=$GENESIS_TIMESTAMP npx hardhat genesis-l1 \
+    L1_GENESIS_TIMESTAMP=$L1_GENESIS_TIMESTAMP npx hardhat genesis-l1 \
         --outfile genesis-l1.json
     mv genesis-l1.json ../../.devnet/genesis-l1.json
   )
@@ -89,7 +89,7 @@ if [ ! -d $CONTRACTS_BEDROCK/deployments/$NETWORK ]; then
   (
     echo "Deploying contracts."
     cd $CONTRACTS_BEDROCK
-    L2OO_STARTING_BLOCK_TIMESTAMP=$GENESIS_TIMESTAMP yarn hardhat --network $NETWORK deploy
+    L1_GENESIS_TIMESTAMP=$L1_GENESIS_TIMESTAMP yarn hardhat --network $NETWORK deploy
   )
 else
   echo "Contracts already deployed, skipping."
@@ -99,7 +99,7 @@ if [ ! -f ./.devnet/genesis-l2.json ]; then
     (
       echo "Creating L2 genesis file."
       cd $CONTRACTS_BEDROCK
-      L2OO_STARTING_BLOCK_TIMESTAMP=$GENESIS_TIMESTAMP npx hardhat --network $NETWORK genesis-l2
+      L1_GENESIS_TIMESTAMP=$L1_GENESIS_TIMESTAMP npx hardhat --network $NETWORK genesis-l2
       mv genesis.json ../../.devnet/genesis-l2.json
       echo "Created L2 genesis."
     )
@@ -120,7 +120,7 @@ if [ ! -f ./.devnet/rollup.json ]; then
     (
       echo "Building rollup config..."
       cd $CONTRACTS_BEDROCK
-      L2OO_STARTING_BLOCK_TIMESTAMP=$GENESIS_TIMESTAMP npx hardhat --network $NETWORK rollup-config
+      L1_GENESIS_TIMESTAMP=$L1_GENESIS_TIMESTAMP npx hardhat --network $NETWORK rollup-config
       mv rollup.json ../../.devnet/rollup.json
     )
 else
diff --git a/packages/contracts-bedrock/deploy-config/devnetL1.ts b/packages/contracts-bedrock/deploy-config/devnetL1.ts
index b52637588c79..183398b51331 100644
--- a/packages/contracts-bedrock/deploy-config/devnetL1.ts
+++ b/packages/contracts-bedrock/deploy-config/devnetL1.ts
@@ -2,19 +2,20 @@ import { ethers } from 'ethers'
 
 const { env } = process
 
-const startingTimestamp =
-  typeof env.L2OO_STARTING_BLOCK_TIMESTAMP === 'string'
-    ? ethers.BigNumber.from(env.L2OO_STARTING_BLOCK_TIMESTAMP).toNumber()
+const l1GenesisTimestamp =
+  typeof env.L1_GENESIS_TIMESTAMP === 'string'
+    ? ethers.BigNumber.from(env.L1_GENESIS_TIMESTAMP).toNumber()
     : Math.floor(Date.now() / 1000)
 
 const config = {
   submissionInterval: 6,
   genesisOutput: ethers.constants.HashZero,
   historicalBlocks: 0,
+  l1StartingBlockTag: 'earliest',
   startingBlockNumber: 0,
   l2BlockTime: 2,
 
-  startingTimestamp,
+  l1GenesisTimestamp,
   sequencerAddress: '0x70997970C51812dc3A010C7d01b50e0d17dc79C8',
 
   l2CrossDomainMessengerOwner: ethers.constants.AddressZero,
diff --git a/packages/contracts-bedrock/deploy-config/goerli.ts b/packages/contracts-bedrock/deploy-config/goerli.ts
index 3398fd6eb33c..93347179520e 100644
--- a/packages/contracts-bedrock/deploy-config/goerli.ts
+++ b/packages/contracts-bedrock/deploy-config/goerli.ts
@@ -1,7 +1,8 @@
 import { ethers } from 'ethers'
 
 const sequencerAddress = '0x6c23a0dcdfc44b7a57bed148de598895e398d984'
-const startingTimestamp = 1658777882
+const l1StartingBlockTag =
+  '0xafce66a0a2446856112e4069b275ad32b1f4a607888f9c4c59eddf9be81f8670'
 
 const config = {
   submissionInterval: 6,
@@ -9,7 +10,7 @@ const config = {
   historicalBlocks: 0,
   startingBlockNumber: 0,
   l2BlockTime: 2,
-  startingTimestamp,
+  l1StartingBlockTag,
   sequencerAddress,
 
   l2CrossDomainMessengerOwner: ethers.constants.AddressZero,
diff --git a/packages/contracts-bedrock/deploy-config/hardhat.ts b/packages/contracts-bedrock/deploy-config/hardhat.ts
index 217c63a20321..596c5b03c625 100644
--- a/packages/contracts-bedrock/deploy-config/hardhat.ts
+++ b/packages/contracts-bedrock/deploy-config/hardhat.ts
@@ -2,9 +2,9 @@ import { ethers } from 'ethers'
 
 const { env } = process
 
-const startingTimestamp =
-  typeof env.L2OO_STARTING_BLOCK_TIMESTAMP === 'string'
-    ? ethers.BigNumber.from(env.L2OO_STARTING_BLOCK_TIMESTAMP).toNumber()
+const l1GenesisTimestamp =
+  typeof env.L1_GENESIS_TIMESTAMP === 'string'
+    ? ethers.BigNumber.from(env.L1_GENESIS_TIMESTAMP).toNumber()
     : Math.floor(Date.now() / 1000)
 
 const config = {
@@ -12,8 +12,9 @@ const config = {
   genesisOutput: ethers.constants.HashZero,
   historicalBlocks: 0,
   startingBlockNumber: 0,
+  l1StartingBlockTag: 'earliest',
   l2BlockTime: 2,
-  startingTimestamp,
+  l1GenesisTimestamp,
   sequencerAddress: '0x70997970C51812dc3A010C7d01b50e0d17dc79C8',
   maxSequencerDrift: 10,
   sequencerWindowSize: 4,
diff --git a/packages/contracts-bedrock/deploy/000-L2OutputOracle.deploy.ts b/packages/contracts-bedrock/deploy/000-L2OutputOracle.deploy.ts
index 0cc44305e7b0..c7602623ebc9 100644
--- a/packages/contracts-bedrock/deploy/000-L2OutputOracle.deploy.ts
+++ b/packages/contracts-bedrock/deploy/000-L2OutputOracle.deploy.ts
@@ -10,13 +10,10 @@ const deployFn: DeployFunction = async (hre) => {
   const { deployer } = await hre.getNamedAccounts()
   const { deployConfig } = hre
 
-  if (
-    typeof deployConfig.startingTimestamp !== 'number' ||
-    isNaN(deployConfig.startingTimestamp)
-  ) {
-    throw new Error(
-      'Cannot deploy L2OutputOracle without specifying a valid startingTimestamp.'
-    )
+  const l1 = hre.ethers.getDefaultProvider()
+  const l1StartingBlock = await l1.getBlock(deployConfig.l1StartingBlockTag)
+  if (l1StartingBlock === null) {
+    throw new Error(`Cannot fetch block tag ${deployConfig.l1StartingBlockTag}`)
   }
 
   await deploy('L2OutputOracleProxy', {
@@ -34,7 +31,7 @@ const deployFn: DeployFunction = async (hre) => {
       deployConfig.genesisOutput,
       deployConfig.historicalBlocks,
       deployConfig.startingBlockNumber,
-      deployConfig.startingTimestamp,
+      l1StartingBlock.timestamp,
       deployConfig.l2BlockTime,
       deployConfig.sequencerAddress,
       deployConfig.outputOracleOwner,
@@ -84,7 +81,7 @@ const deployFn: DeployFunction = async (hre) => {
   }
 
   const startingTimestamp = await L2OutputOracle.STARTING_TIMESTAMP()
-  if (!startingTimestamp.eq(BigNumber.from(deployConfig.startingTimestamp))) {
+  if (!startingTimestamp.eq(BigNumber.from(l1StartingBlock.timestamp))) {
     throw new Error('starting timestamp misconfigured')
   }
   const l2BlockTime = await L2OutputOracle.L2_BLOCK_TIME()
diff --git a/packages/contracts-bedrock/hardhat.config.ts b/packages/contracts-bedrock/hardhat.config.ts
index de235ce8f315..e07578243e41 100644
--- a/packages/contracts-bedrock/hardhat.config.ts
+++ b/packages/contracts-bedrock/hardhat.config.ts
@@ -74,18 +74,15 @@ const config: HardhatUserConfig = {
     historicalBlocks: {
       type: 'number',
     },
-    startingBlockNumber: {
-      type: 'number',
-    },
-    startingTimestamp: {
-      type: 'number',
-    },
     sequencerAddress: {
       type: 'address',
     },
     outputOracleOwner: {
       type: 'address',
     },
+    l1StartingBlockTag: {
+      type: 'string',
+    },
   },
   external: {
     contracts: [
diff --git a/packages/contracts-bedrock/tasks/genesis-l1.ts b/packages/contracts-bedrock/tasks/genesis-l1.ts
index e01043582f54..deac7649c116 100644
--- a/packages/contracts-bedrock/tasks/genesis-l1.ts
+++ b/packages/contracts-bedrock/tasks/genesis-l1.ts
@@ -61,7 +61,7 @@ task('genesis-l1', 'create a genesis config')
       }
     }
 
-    const timestamp = hre.deployConfig.startingTimestamp
+    const timestamp = hre.deployConfig.l1GenesisTimestamp
     if (timestamp === undefined) {
       throw new Error('Must configure starting block timestamp')
     }
diff --git a/packages/contracts-bedrock/tasks/genesis-l2.ts b/packages/contracts-bedrock/tasks/genesis-l2.ts
index 322faa40fbe6..60a3de25e4c6 100644
--- a/packages/contracts-bedrock/tasks/genesis-l2.ts
+++ b/packages/contracts-bedrock/tasks/genesis-l2.ts
@@ -462,8 +462,12 @@ task('genesis-l2', 'create a genesis config')
       }
     }
 
-    const portal = await hre.deployments.get('OptimismPortalProxy')
-    const l1StartingBlock = await l1.getBlock(portal.receipt.blockHash)
+    const l1StartingBlock = await l1.getBlock(deployConfig.l1StartingBlockTag)
+    if (l1StartingBlock === null) {
+      throw new Error(
+        `Cannot fetch block tag ${deployConfig.l1StartingBlockTag}`
+      )
+    }
 
     if (l1StartingBlock === null) {
       console.log(`Unable to fetch L1 starting timestamp`)
diff --git a/packages/contracts-bedrock/tasks/rollup-config.ts b/packages/contracts-bedrock/tasks/rollup-config.ts
index 268d2b39e47f..f80b0d523341 100644
--- a/packages/contracts-bedrock/tasks/rollup-config.ts
+++ b/packages/contracts-bedrock/tasks/rollup-config.ts
@@ -23,13 +23,18 @@ task('rollup-config', 'create a genesis config')
     const l2Genesis = await l2.getBlock('earliest')
 
     const portal = await hre.deployments.get('OptimismPortalProxy')
-    const l1StartingBlock = await l1.getBlock(portal.receipt.blockHash)
+    const l1StartingBlock = await l1.getBlock(deployConfig.l1StartingBlockTag)
+    if (l1StartingBlock === null) {
+      throw new Error(
+        `Cannot fetch block tag ${deployConfig.l1StartingBlockTag}`
+      )
+    }
 
     const config: OpNodeConfig = {
       genesis: {
         l1: {
-          hash: portal.receipt.blockHash,
-          number: portal.receipt.blockNumber,
+          hash: l1StartingBlock.hash,
+          number: l1StartingBlock.number,
         },
         l2: {
           hash: l2Genesis.hash,
diff --git a/packages/contracts-bedrock/tsconfig.json b/packages/contracts-bedrock/tsconfig.json
index 5cb4fda3c546..e5df8a66de31 100644
--- a/packages/contracts-bedrock/tsconfig.json
+++ b/packages/contracts-bedrock/tsconfig.json
@@ -4,7 +4,5 @@
     "rootDir": "./src",
     "outDir": "./dist"
   },
-  "include": [
-    "src/**/*"
-  ]
+  "include": ["src/**/*"]
 }