diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f406c6a209..b3718926f6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,6 +9,7 @@ on:
     branches:
       - master
       - develop
+      - integration
 
 jobs:
   test:
@@ -126,7 +127,10 @@ jobs:
         run: ./scripts/build-brotli.sh -w -d
 
       - name: Build
-        run: make build test-go-deps -j
+        run: make build -j
+
+      - name: test-go-deps
+        run: make --debug test-go-deps
 
       - name: Build all lint dependencies
         run: make -j build-node-deps
@@ -169,7 +173,7 @@ jobs:
         if: matrix.test-mode == 'challenge'
         run:  |
           packages=`go list ./...`
-          gotestsum --format short-verbose --packages="$packages" --rerun-fails=1 -- ./... -coverprofile=coverage.txt -covermode=atomic -coverpkg=./...,./go-ethereum/... -tags=challengetest -run=TestChallenge
+          gotestsum --format short-verbose --packages="$packages" --rerun-fails=1 -- -timeout 20m ./... -coverprofile=coverage.txt -covermode=atomic -coverpkg=./...,./go-ethereum/... -tags=challengetest -run=TestChallenge
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v2
diff --git a/arbos/block_processor.go b/arbos/block_processor.go
index 9147066eca..5d0c70f3f1 100644
--- a/arbos/block_processor.go
+++ b/arbos/block_processor.go
@@ -159,8 +159,32 @@ func ProduceBlock(
 	}
 
 	hooks := NoopSequencingHooks()
+
+	// Espresso-specific validation
+	// TODO test: https://github.com/EspressoSystems/espresso-sequencer/issues/772
+	if chainConfig.Espresso {
+		jst := message.Header.BlockJustification
+		if jst == nil {
+			return nil, nil, errors.New("batch missing espresso justification")
+
+		}
+		hotshotHeader := jst.Header
+		if *lastHotShotCommitment != hotshotHeader.Commit() {
+			return nil, nil, errors.New("invalid hotshot header")
+		}
+		var roots = []*espresso.NmtRoot{&hotshotHeader.TransactionsRoot}
+		var proofs = []*espresso.NmtProof{&message.Header.BlockJustification.Proof}
+		// If the validation function below were not mocked, we would need to serialize the transactions
+		// in the batch here. To avoid the unnecessary overhead, we provide an empty array instead.
+		var txs []espresso.Bytes
+		err := espresso.ValidateBatchTransactions(chainConfig.ChainID.Uint64(), roots, proofs, txs)
+		if err != nil {
+			return nil, nil, errors.New("failed to validate namespace proof)")
+		}
+	}
+
 	return ProduceBlockAdvanced(
-		message.Header, txes, delayedMessagesRead, lastBlockHeader, lastHotShotCommitment, statedb, chainContext, chainConfig, hooks,
+		message.Header, txes, delayedMessagesRead, lastBlockHeader, statedb, chainContext, chainConfig, hooks,
 	)
 }
 
@@ -170,7 +194,6 @@ func ProduceBlockAdvanced(
 	txes types.Transactions,
 	delayedMessagesRead uint64,
 	lastBlockHeader *types.Header,
-	lastHotShotCommitment *espresso.Commitment,
 	statedb *state.StateDB,
 	chainContext core.ChainContext,
 	chainConfig *params.ChainConfig,
@@ -194,31 +217,6 @@ func ProduceBlockAdvanced(
 		l1Timestamp:   l1Header.Timestamp,
 	}
 
-	// Espresso-specific validation
-	// TODO test: https://github.com/EspressoSystems/espresso-sequencer/issues/772
-	var defaultCommitment espresso.Commitment
-
-	if lastHotShotCommitment != nil && !lastHotShotCommitment.Equals(defaultCommitment) {
-		jst := l1Header.BlockJustification
-		if jst == nil {
-			return nil, nil, fmt.Errorf("batch missing espresso justification, provided commitment:  %v", lastHotShotCommitment)
-
-		}
-		hotshotHeader := jst.Header
-		if *lastHotShotCommitment != hotshotHeader.Commit() {
-			return nil, nil, errors.New("invalid hotshot header")
-		}
-		var roots = []*espresso.NmtRoot{&hotshotHeader.TransactionsRoot}
-		var proofs = []*espresso.NmtProof{&l1Header.BlockJustification.Proof}
-		// If the validation function below were not mocked, we would need to serialize the transactions
-		// in the batch here. To avoid the unnecessary overhead, we provide an empty array instead.
-		var txs []espresso.Bytes
-		err := espresso.ValidateBatchTransactions(chainConfig.ChainID.Uint64(), roots, proofs, txs)
-		if err != nil {
-			return nil, nil, errors.New("failed to validate namespace proof)")
-		}
-	}
-
 	header := createNewHeader(lastBlockHeader, l1Info, state, chainConfig)
 	signer := types.MakeSigner(chainConfig, header.Number, header.Time)
 	// Note: blockGasLeft will diverge from the actual gas left during execution in the event of invalid txs,
diff --git a/arbos/parse_l2.go b/arbos/parse_l2.go
index 88018fdfcf..f13fc6ad3f 100644
--- a/arbos/parse_l2.go
+++ b/arbos/parse_l2.go
@@ -20,6 +20,7 @@ import (
 
 type InfallibleBatchFetcher func(batchNum uint64, batchHash common.Hash) []byte
 
+// TODO: parse espresso justification https://github.com/EspressoSystems/nitro-espresso-integration/pull/14/files
 func ParseL2Transactions(msg *arbostypes.L1IncomingMessage, chainId *big.Int, batchFetcher InfallibleBatchFetcher) (types.Transactions, error) {
 	if len(msg.L2msg) > arbostypes.MaxL2MessageSize {
 		// ignore the message if l2msg is too large
diff --git a/execution/gethexec/executionengine.go b/execution/gethexec/executionengine.go
index 5d099cee00..d4570870e0 100644
--- a/execution/gethexec/executionengine.go
+++ b/execution/gethexec/executionengine.go
@@ -294,7 +294,6 @@ func (s *ExecutionEngine) sequenceTransactionsWithBlockMutex(header *arbostypes.
 		txes,
 		delayedMessagesRead,
 		lastBlockHeader,
-		nil,
 		statedb,
 		s.bc,
 		s.bc.Config(),