diff --git a/stack-orchestrator/config/fixturenet-eth/fixturenet-eth.env b/stack-orchestrator/config/fixturenet-eth/fixturenet-eth.env
index 2bf489a..695c8fa 100644
--- a/stack-orchestrator/config/fixturenet-eth/fixturenet-eth.env
+++ b/stack-orchestrator/config/fixturenet-eth/fixturenet-eth.env
@@ -22,4 +22,7 @@ CERC_STATEDIFF_DB_LOG_STATEMENTS="${CERC_STATEDIFF_DB_LOG_STATEMENTS:-false}"
 CERC_STATEDIFF_WORKERS=2
 
 CERC_GETH_VMODULE="statediff/*=5,rpc/*=5"
-CERC_GETH_VERBOSITY=${CERC_GETH_VERBOSITY:-3}
\ No newline at end of file
+CERC_GETH_VERBOSITY=${CERC_GETH_VERBOSITY:-3}
+
+# Used by Lighthouse
+SECONDS_PER_ETH1_BLOCK=${SECONDS_PER_ETH1_BLOCK:-3}
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/Dockerfile b/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/Dockerfile
deleted file mode 100644
index 4fa8d0f..0000000
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/Dockerfile
+++ /dev/null
@@ -1,28 +0,0 @@
-FROM skylenet/ethereum-genesis-generator@sha256:210353ce7c898686bc5092f16c61220a76d357f51eff9c451e9ad1b9ad03d4d3 AS ethgen
-
-FROM golang:1.20-alpine as builder
-
-RUN apk add --no-cache python3 py3-pip
-
-COPY genesis /opt/genesis
-
-# Install ethereum-genesis-generator tools
-COPY --from=ethgen /usr/local/bin/eth2-testnet-genesis /usr/local/bin/
-COPY --from=ethgen /usr/local/bin/eth2-val-tools /usr/local/bin/
-COPY --from=ethgen /apps /apps
-RUN cd /apps/el-gen && pip3 install --break-system-packages -r requirements.txt
-# web3==5.24.0 used by el-gen is broken on python 3.11
-RUN pip3 install --break-system-packages --upgrade "web3==6.5.0"
-RUN pip3 install --break-system-packages --upgrade "typing-extensions"
-
-# Build genesis config
-RUN apk add --no-cache make bash envsubst jq
-RUN cd /opt/genesis && make genesis-el
-
-# Snag the genesis block info.
-RUN go install github.com/cerc-io/eth-dump-genblock@latest
-RUN eth-dump-genblock /opt/genesis/build/el/geth.json > /opt/genesis/build/el/genesis_block.json
-
-FROM alpine:latest
-
-COPY --from=builder /opt/genesis /opt/genesis
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/build.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/build.sh
deleted file mode 100755
index dac3676..0000000
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/build.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-#!/usr/bin/env bash
-# Build cerc/fixturenet-eth-genesis-premerge
-
-source ${CERC_CONTAINER_BASE_DIR}/build-base.sh
-
-SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
-
-docker build -t cerc/fixturenet-eth-genesis-premerge:local -f ${SCRIPT_DIR}/Dockerfile ${build_command_args} $SCRIPT_DIR
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/Makefile b/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/Makefile
deleted file mode 100644
index a1eef57..0000000
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/Makefile
+++ /dev/null
@@ -1,13 +0,0 @@
-.PHONY: build
-build: genesis
-
-.PHONY: genesis
-genesis: genesis-el
-
-.PHONY: genesis-el
-genesis-el:
-	cd el; ./build_el.sh
-
-.PHONY: clean
-clean:
-	rm -rf build
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/accounts/import_keys.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/accounts/import_keys.sh
deleted file mode 100755
index e8dce0e..0000000
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/accounts/import_keys.sh
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh
-
-ACCOUNT_PASSWORD=${ACCOUNT_PASSWORD:-secret1212}
-
-for line in `cat ../build/el/accounts.csv`; do
-  BIP44_PATH="`echo "$line" | cut -d',' -f1`"
-  ADDRESS="`echo "$line" | cut -d',' -f2`"
-  PRIVATE_KEY="`echo "$line" | cut -d',' -f3`"
-
-  echo "$ACCOUNT_PASSWORD" > .pw.$$
-  echo "$PRIVATE_KEY" | sed 's/0x//' > .key.$$
-
-  echo ""
-  echo "$ADDRESS"
-  geth account import --datadir=~/ethdata --password .pw.$$ .key.$$
-  rm -f .pw.$$ .key.$$
-done
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/accounts/mnemonic_to_csv.py b/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/accounts/mnemonic_to_csv.py
deleted file mode 100644
index 1e6d10f..0000000
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/accounts/mnemonic_to_csv.py
+++ /dev/null
@@ -1,16 +0,0 @@
-from web3.auto import w3
-import ruamel.yaml as yaml
-import sys
-
-w3.eth.account.enable_unaudited_hdwallet_features()
-
-testnet_config_path = "genesis-config.yaml"
-if len(sys.argv) > 1:
-    testnet_config_path = sys.argv[1]
-
-with open(testnet_config_path) as stream:
-    data = yaml.safe_load(stream)
-
-for key, value in data['el_premine'].items():
-    acct = w3.eth.account.from_mnemonic(data['mnemonic'], account_path=key, passphrase='')
-    print("%s,%s,%s" % (key, acct.address, acct.key.hex()))
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/el/build_el.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/el/build_el.sh
deleted file mode 100755
index 9ff77fa..0000000
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/el/build_el.sh
+++ /dev/null
@@ -1,40 +0,0 @@
-#!/usr/bin/env bash
-set -e
-
-# See: https://github.com/skylenet/ethereum-genesis-generator/blob/master/entrypoint.sh
-
-rm -rf ../build/el
-mkdir -p ../build/el
-
-tmp_dir=$(mktemp -d -t ci-XXXXXXXXXX)
-envsubst < el-config.yaml > $tmp_dir/genesis-config.yaml
-
-ttd=`cat $tmp_dir/genesis-config.yaml | grep terminal_total_difficulty | awk '{ print $2 }'`
-homestead_block=`cat $tmp_dir/genesis-config.yaml | grep homestead_block | awk '{ print $2 }'`
-eip150_block=`cat $tmp_dir/genesis-config.yaml | grep eip150_block | awk '{ print $2 }'`
-eip155_block=`cat $tmp_dir/genesis-config.yaml | grep eip155_block | awk '{ print $2 }'`
-eip158_block=`cat $tmp_dir/genesis-config.yaml | grep eip158_block | awk '{ print $2 }'`
-byzantium_block=`cat $tmp_dir/genesis-config.yaml | grep byzantium_block | awk '{ print $2 }'`
-constantinople_block=`cat $tmp_dir/genesis-config.yaml | grep constantinople_block | awk '{ print $2 }'`
-petersburg_block=`cat $tmp_dir/genesis-config.yaml | grep petersburg_block | awk '{ print $2 }'`
-istanbul_block=`cat $tmp_dir/genesis-config.yaml | grep istanbul_block | awk '{ print $2 }'`
-berlin_block=`cat $tmp_dir/genesis-config.yaml | grep berlin_block | awk '{ print $2 }'`
-london_block=`cat $tmp_dir/genesis-config.yaml | grep london_block | awk '{ print $2 }'`
-merge_fork_block=`cat $tmp_dir/genesis-config.yaml | grep merge_fork_block | awk '{ print $2 }'`
-
-python3 /apps/el-gen/genesis_geth.py $tmp_dir/genesis-config.yaml | \
-  jq ".config.terminalTotalDifficulty=$ttd" | \
-  jq ".config.homesteadBlock=$homestead_block" | \
-  jq ".config.eip150Block=$eip150_block" | \
-  jq ".config.eip155Block=$eip155_block" | \
-  jq ".config.eip158Block=$eip158_block" | \
-  jq ".config.byzantiumBlock=$byzantium_block" | \
-  jq ".config.constantinopleBlock=$constantinople_block" | \
-  jq ".config.petersburgBlock=$petersburg_block" | \
-  jq ".config.istanbulBlock=$istanbul_block" | \
-  jq ".config.berlinBlock=$berlin_block" | \
-  jq ".config.londonBlock=$london_block" | \
-  jq ".config.mergeForkBlock=$merge_fork_block" | \
-  jq ".config.mergeNetsplitBlock=$merge_fork_block" \
-  > ../build/el/geth.json
-python3 ../accounts/mnemonic_to_csv.py $tmp_dir/genesis-config.yaml > ../build/el/accounts.csv
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/el/el-config.yaml b/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/el/el-config.yaml
deleted file mode 100644
index 8bcb0fa..0000000
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-genesis-premerge/genesis/el/el-config.yaml
+++ /dev/null
@@ -1,31 +0,0 @@
-mnemonic: "viable ketchup woman library opinion copy rhythm attend rose knock penalty practice photo bundle budget dentist enter round bind holiday useful arch danger lobster"
-el_premine:
-  "m/44'/60'/0'/0/0": 10000000ETH
-  "m/44'/60'/0'/0/1": 10000000ETH
-  "m/44'/60'/0'/0/2": 10000000ETH
-  "m/44'/60'/0'/0/3": 10000000ETH
-  "m/44'/60'/0'/0/4": 10000000ETH
-  "m/44'/60'/0'/0/5": 10000000ETH
-el_premine_addrs: {}
-chain_id: 1212
-deposit_contract_address: "0x1212121212121212121212121212121212121212"
-genesis_timestamp: 0
-terminal_total_difficulty: 1000
-homestead_block: 1
-eip150_block: 1
-eip155_block: 1
-eip158_block: 1
-byzantium_block: 1
-constantinople_block: 1
-petersburg_block: 1
-istanbul_block: 1
-berlin_block: 1
-london_block: 1
-merge_fork_block: 1
-
-clique:
-  enabled: false
-  signers:
-    - 36d56343bc308d4ffaac2f793d121aba905fa6cc
-    - 5e762d4a3847cadaf40a4b0c39574b0ff6698c78
-    - 15d7acc1019fdf8ab4f0f7bd31ec1487ecb5a2bd
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/Dockerfile b/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/Dockerfile
index e904686..3afb524 100644
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/Dockerfile
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/Dockerfile
@@ -1,5 +1,5 @@
-FROM cerc/fixturenet-eth-genesis-premerge:local as fnetgen
-FROM ethereum/client-go:release-1.11 as geth
+FROM cerc/fixturenet-eth-genesis-postmerge:local as fnetgen
+FROM ethereum/client-go:release-1.14 as geth
 
 # Using the same golang image as used to build geth: https://github.com/cerc-io/go-ethereum/blob/HEAD/Dockerfile
 FROM golang:1.21-alpine as delve
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/run-el.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/run-el.sh
index be35c8b..f84befd 100755
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/run-el.sh
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-geth/run-el.sh
@@ -6,7 +6,7 @@ fi
 
 ETHERBASE=`cat /opt/testnet/build/el/accounts.csv | head -1 | cut -d',' -f2`
 NETWORK_ID=`cat /opt/testnet/el/el-config.yaml | grep 'chain_id' | awk '{ print $2 }'`
-NETRESTRICT=`ip addr | grep 'inet ' | grep -v '127.0' | head -1 | awk '{print $2}'`
+NETRESTRICT=`ip addr | grep -w inet | grep -v '127.0' | awk '{print $2}'`
 CERC_ETH_DATADIR="${CERC_ETH_DATADIR:-$HOME/ethdata}"
 CERC_PLUGINS_DIR="${CERC_PLUGINS_DIR:-/usr/local/lib/plugeth}"
 
@@ -50,6 +50,65 @@ else
 
     echo -n "$JWT" > /opt/testnet/build/el/jwtsecret
 
+    if [ "$CERC_RUN_STATEDIFF" == "detect" ] && [ -n "$CERC_STATEDIFF_DB_HOST" ]; then
+      dig_result=$(dig $CERC_STATEDIFF_DB_HOST +short)
+      dig_status_code=$?
+      if [[ $dig_status_code = 0 && -n $dig_result ]]; then
+        echo "Statediff DB at $CERC_STATEDIFF_DB_HOST"
+        CERC_RUN_STATEDIFF="true"
+      else
+        echo "No statediff DB available."
+        CERC_RUN_STATEDIFF="false"
+      fi
+    fi
+
+    STATEDIFF_OPTS=""
+    if [ "$CERC_RUN_STATEDIFF" == "true" ]; then
+      ready=0
+      echo "Waiting for statediff DB..."
+      while [ $ready -eq 0 ]; do
+        sleep 1
+        export PGPASSWORD="$CERC_STATEDIFF_DB_PASSWORD"
+        result=$(psql -h "$CERC_STATEDIFF_DB_HOST" \
+          -p "$CERC_STATEDIFF_DB_PORT" \
+          -U "$CERC_STATEDIFF_DB_USER" \
+          -d "$CERC_STATEDIFF_DB_NAME" \
+          -t -c 'select max(version_id) from goose_db_version;' 2>/dev/null | awk '{ print $1 }')
+        if [ -n "$result" ]; then
+          echo "DB ready..."
+          if [ $result -ge $CERC_STATEDIFF_DB_GOOSE_MIN_VER ]; then
+            ready=1
+          else
+            echo "DB not at required version (want $CERC_STATEDIFF_DB_GOOSE_MIN_VER, have $result)"
+          fi
+        fi
+      done
+      STATEDIFF_OPTS="--statediff \
+      --statediff.db.host=$CERC_STATEDIFF_DB_HOST \
+      --statediff.db.name=$CERC_STATEDIFF_DB_NAME \
+      --statediff.db.nodeid=$CERC_STATEDIFF_DB_NODE_ID \
+      --statediff.db.password=$CERC_STATEDIFF_DB_PASSWORD \
+      --statediff.db.port=$CERC_STATEDIFF_DB_PORT \
+      --statediff.db.user=$CERC_STATEDIFF_DB_USER \
+      --statediff.db.logstatements=${CERC_STATEDIFF_DB_LOG_STATEMENTS:-false} \
+      --statediff.db.copyfrom=${CERC_STATEDIFF_DB_COPY_FROM:-true} \
+      --statediff.waitforsync=true \
+      --statediff.workers=${CERC_STATEDIFF_WORKERS:-1} \
+      --statediff.writing=true"
+
+      if [ -d "${CERC_PLUGINS_DIR}" ]; then
+        # With plugeth, we separate the statediff options by prefixing with ' -- '
+        STATEDIFF_OPTS="--pluginsdir "${CERC_PLUGINS_DIR}" -- ${STATEDIFF_OPTS}"
+      fi
+    fi
+
+    OTHER_OPTS=""
+    # miner options were removed in v1.12
+    GETH_VERSION=$(geth --version | grep -io '[0-9][0-9a-z.-]*')
+    if echo -e "$GETH_VERSION\n1.12" | sort -Vc; then
+      OTHER_OPTS="--miner.threads=1"
+    fi
+
     $START_CMD \
       --datadir="${CERC_ETH_DATADIR}" \
       --bootnodes="${ENODE}" \
@@ -57,7 +116,7 @@ else
       --http \
       --http.addr="0.0.0.0" \
       --http.vhosts="*" \
-      --http.api="${CERC_GETH_HTTP_APIS:-eth,web3,net,admin,personal,debug}" \
+      --http.api="${CERC_GETH_HTTP_APIS:-eth,web3,net,admin,personal,debug,statediff}" \
       --http.corsdomain="*" \
       --authrpc.addr="0.0.0.0" \
       --authrpc.vhosts="*" \
@@ -65,7 +124,7 @@ else
       --ws \
       --ws.addr="0.0.0.0" \
       --ws.origins="*" \
-      --ws.api="${CERC_GETH_WS_APIS:-eth,web3,net,admin,personal,debug}" \
+      --ws.api="${CERC_GETH_WS_APIS:-eth,web3,net,admin,personal,debug,statediff}" \
       --http.corsdomain="*" \
       --networkid="${NETWORK_ID}" \
       --netrestrict="${NETRESTRICT}" \
@@ -74,12 +133,13 @@ else
       --cache.preimages \
       --syncmode=full \
       --mine \
-      --miner.threads=1 \
       --metrics \
       --metrics.addr="0.0.0.0" \
       --verbosity=${CERC_GETH_VERBOSITY:-3} \
-      --log.vmodule="${CERC_GETH_VMODULE}" \
+      --log.vmodule="${CERC_GETH_VMODULE:-statediff/*=5}" \
       --miner.etherbase="${ETHERBASE}" \
+      ${OTHER_OPTS} \
+      ${STATEDIFF_OPTS} \
       &
 
     geth_pid=$!
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/Dockerfile b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/Dockerfile
index 090c49f..3e91363 100644
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/Dockerfile
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/Dockerfile
@@ -1,6 +1,5 @@
 FROM cerc/lighthouse-cli:local AS lcli
-FROM skylenet/ethereum-genesis-generator@sha256:210353ce7c898686bc5092f16c61220a76d357f51eff9c451e9ad1b9ad03d4d3 AS ethgen
-FROM cerc/fixturenet-eth-genesis-premerge:local AS fnetgen
+FROM cerc/fixturenet-eth-genesis-postmerge:local AS fnetgen
 
 FROM cerc/lighthouse:local
 
@@ -12,16 +11,13 @@ RUN apt-get update && apt-get -y upgrade && apt-get install -y --no-install-reco
   && apt-get clean \
   && rm -rf /var/lib/apt/lists/*
 
-COPY genesis /opt/testnet
-COPY run-cl.sh /opt/testnet/run.sh
-
 COPY --from=lcli /usr/local/bin/lcli /usr/local/bin/lcli
-COPY --from=ethgen /usr/local/bin/eth2-testnet-genesis /usr/local/bin/eth2-testnet-genesis
-COPY --from=ethgen /usr/local/bin/eth2-val-tools /usr/local/bin/eth2-val-tools
-COPY --from=ethgen /apps /apps
 COPY --from=fnetgen /opt/genesis/el /opt/testnet/el
 COPY --from=fnetgen /opt/genesis/build/el /opt/testnet/build/el
 
+COPY genesis /opt/testnet
+COPY run-cl.sh /opt/testnet/run.sh
+
 RUN cd /opt/testnet && make genesis-cl
 
 # Work around some bugs in lcli where the default path is always used.
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/beacon_node.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/beacon_node.sh
index 1f90615..7e92f49 100755
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/beacon_node.sh
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/beacon_node.sh
@@ -10,7 +10,6 @@ set -Eeuo pipefail
 source ./vars.env
 
 SUBSCRIBE_ALL_SUBNETS=
-DEBUG_LEVEL=${DEBUG_LEVEL:-debug}
 
 # Get positional arguments
 data_dir=$DATADIR/node_${NODE_NUMBER}
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/bootnode.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/bootnode.sh
index bda3b78..15aee6e 100755
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/bootnode.sh
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/bootnode.sh
@@ -9,8 +9,6 @@ set -Eeuo pipefail
 
 source ./vars.env
 
-DEBUG_LEVEL=${1:-info}
-
 echo "Starting bootnode"
 
 # Clean up existing ENR dir to avoid node connectivity issues on a restart
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/build_cl.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/build_cl.sh
index 50b3e4e..5157b38 100755
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/build_cl.sh
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/build_cl.sh
@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
 
+# See https://github.com/sigp/lighthouse/scripts/local_testnet/setup.sh
 #
 # Deploys the deposit contract and makes deposits for $VALIDATOR_COUNT insecure deterministic validators.
 # Produces a testnet specification and a genesis state where the genesis time
@@ -24,23 +25,26 @@ echo "(Note: errors of the form 'WARN: Scrypt parameters are too weak...' below
 lcli \
   new-testnet \
   --spec $SPEC_PRESET \
-  --deposit-contract-address $ETH1_DEPOSIT_CONTRACT_ADDRESS \
   --testnet-dir $TESTNET_DIR \
+  --deposit-contract-address $ETH1_DEPOSIT_CONTRACT_ADDRESS \
   --min-genesis-active-validator-count $GENESIS_VALIDATOR_COUNT \
   --validator-count $VALIDATOR_COUNT \
   --min-genesis-time $GENESIS_TIME \
   --genesis-delay $GENESIS_DELAY \
   --genesis-fork-version $GENESIS_FORK_VERSION \
   --altair-fork-epoch $ALTAIR_FORK_EPOCH \
-  --bellatrix-fork-epoch $MERGE_FORK_EPOCH \
+  --bellatrix-fork-epoch $BELLATRIX_FORK_EPOCH \
+  --capella-fork-epoch $CAPELLA_FORK_EPOCH \
+  --deneb-fork-epoch $DENEB_FORK_EPOCH \
   --eth1-id $ETH1_CHAIN_ID \
   --eth1-block-hash $ETH1_BLOCK_HASH \
   --eth1-follow-distance 1 \
   --seconds-per-slot $SECONDS_PER_SLOT \
   --seconds-per-eth1-block $SECONDS_PER_ETH1_BLOCK \
+  --interop-genesis-state \
   --force
 
-echo Specification generated at $TESTNET_DIR.
+echo Specification and genesis.ssz generated at $TESTNET_DIR.
 echo "Generating $VALIDATOR_COUNT validators concurrently... (this may take a while)"
 
 lcli \
@@ -50,13 +54,3 @@ lcli \
   --node-count $BN_COUNT
 
 echo Validators generated with keystore passwords at $DATADIR.
-echo "Building genesis state... (this might take a while)"
-
-lcli \
-  interop-genesis \
-  --spec $SPEC_PRESET \
-  --genesis-time $GENESIS_TIME \
-  --testnet-dir $TESTNET_DIR \
-  $GENESIS_VALIDATOR_COUNT
-
-echo Created genesis state in $TESTNET_DIR
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/validator_client.sh b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/validator_client.sh
index 30168f8..2c65e74 100755
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/validator_client.sh
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/validator_client.sh
@@ -8,8 +8,6 @@ set -Eeuo pipefail
 
 source ./vars.env
 
-DEBUG_LEVEL=info
-
 BUILDER_PROPOSALS=
 
 # Get options
diff --git a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/vars.env b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/vars.env
index 081f8f7..83780b2 100644
--- a/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/vars.env
+++ b/stack-orchestrator/container-build/cerc-fixturenet-eth-lighthouse/genesis/cl/vars.env
@@ -25,7 +25,9 @@ BOOTNODE_PORT=${BOOTNODE_PORT:-4242}
 
 # Hard fork configuration
 ALTAIR_FORK_EPOCH=${ALTAIR_FORK_EPOCH:-0}
-MERGE_FORK_EPOCH=${MERGE_FORK_EPOCH:-0}
+BELLATRIX_FORK_EPOCH=${BELLATRIX_FORK_EPOCH:-0}
+CAPELLA_FORK_EPOCH=${CAPELLA_FORK_EPOCH:-0}
+DENEB_FORK_EPOCH=${DENEB_FORK_EPOCH:-0}
 
 # Spec version (mainnet or minimal)
 SPEC_PRESET=${SPEC_PRESET:-mainnet}
@@ -51,3 +53,6 @@ ETH1_TTD=${ETH1_TTD:-`cat $ETH1_GENESIS_JSON | jq -r '.config.terminalTotalDiffi
 ETH1_DEPOSIT_CONTRACT_ADDRESS=${ETH1_DEPOSIT_CONTRACT_ADDRESS:-`cat $ETH1_CONFIG_YAML | grep 'deposit_contract_address' | awk '{ print $2 }' | sed 's/"//g'`}
 ETH1_DEPOSIT_CONTRACT_BLOCK=${ETH1_DEPOSIT_CONTRACT_BLOCK:-0x0}
 SUGGESTED_FEE_RECIPIENT=`cat ../build/el/accounts.csv | head -1 | cut -d',' -f2`
+
+# --debug-level
+DEBUG_LEVEL=${LIGHTHOUSE_DEBUG_LEVEL:-debug}
diff --git a/stack-orchestrator/container-build/cerc-lighthouse/Dockerfile b/stack-orchestrator/container-build/cerc-lighthouse/Dockerfile
index a5559f6..de32150 100644
--- a/stack-orchestrator/container-build/cerc-lighthouse/Dockerfile
+++ b/stack-orchestrator/container-build/cerc-lighthouse/Dockerfile
@@ -1,9 +1,10 @@
-ARG TAG_SUFFIX="-modern"
-FROM sigp/lighthouse:v4.3.0${TAG_SUFFIX}
+FROM sigp/lighthouse:v5.1.2
 
-RUN apt-get update; apt-get install bash netcat curl less jq wget -y;
+RUN apt-get update && apt-get -y upgrade \
+    && apt-get -y install bash netcat curl less jq wget \
+    && apt-get clean && rm -rf /var/lib/apt/lists/*
 
-WORKDIR /root/
+WORKDIR /root
 ADD start-lighthouse.sh .
 
 ENTRYPOINT [ "./start-lighthouse.sh" ]
diff --git a/stack-orchestrator/container-build/cerc-lighthouse/build.sh b/stack-orchestrator/container-build/cerc-lighthouse/build.sh
index cdc9561..2e9cfe3 100755
--- a/stack-orchestrator/container-build/cerc-lighthouse/build.sh
+++ b/stack-orchestrator/container-build/cerc-lighthouse/build.sh
@@ -6,4 +6,4 @@ source ${CERC_CONTAINER_BASE_DIR}/build-base.sh
 # See: https://stackoverflow.com/a/246128/1701505
 SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
 
-docker build -t cerc/lighthouse:local ${build_command_args} --build-arg TAG_SUFFIX="" ${SCRIPT_DIR}
+docker build -t cerc/lighthouse:local ${build_command_args} ${SCRIPT_DIR}
diff --git a/stack-orchestrator/stacks/fixturenet-eth/stack.yml b/stack-orchestrator/stacks/fixturenet-eth/stack.yml
index e26b3b9..d36a6c9 100644
--- a/stack-orchestrator/stacks/fixturenet-eth/stack.yml
+++ b/stack-orchestrator/stacks/fixturenet-eth/stack.yml
@@ -6,7 +6,7 @@ repos:
 containers:
   - cerc/lighthouse
   - cerc/lighthouse-cli
-  - cerc/fixturenet-eth-genesis-premerge
+  - cerc/fixturenet-eth-genesis-postmerge
   - cerc/fixturenet-eth-geth
   - cerc/fixturenet-eth-lighthouse
 pods:
diff --git a/tests/fixturenet-eth-stack/run-test.sh b/tests/fixturenet-eth-stack/run-test.sh
index 99ac163..9db9d3f 100755
--- a/tests/fixturenet-eth-stack/run-test.sh
+++ b/tests/fixturenet-eth-stack/run-test.sh
@@ -69,7 +69,7 @@ initial_block_number=0
 while [ "$initial_block_number" -eq 0 ]  && [ $elapsed_time -lt $timeout ]; do
   sleep 10
   log_info "Waiting for initial block..."
-  initial_block_number=$($SO_COMMAND deployment --dir $test_deployment_dir exec foundry "cast block-number")
+  initial_block_number=$($SO_COMMAND --stack fixturenet-eth deploy exec foundry "cast block-number")
   current_time=$(date +%s)
   elapsed_time=$((current_time - start_time))
 done
@@ -86,7 +86,7 @@ if [[ $initial_block_number -gt 0 ]]; then
   while [ "$subsequent_block_number" -le $((initial_block_number + 5)) ]  && [ $elapsed_time -lt $timeout ]; do
     sleep 10
     log_info "Waiting for five blocks or $timeout seconds..."
-    subsequent_block_number=$($SO_COMMAND deployment --dir $test_deployment_dir exec foundry "cast block-number")
+    subsequent_block_number=$($SO_COMMAND --stack fixturenet-eth deploy exec foundry "cast block-number")
     current_time=$(date +%s)
     elapsed_time=$((current_time - start_time))
   done
@@ -106,7 +106,7 @@ if [[ $block_number_difference -gt 1 && $block_number_difference -lt 100 ]]; the
 else
   echo "Test failed: block numbers were ${initial_block_number} and ${subsequent_block_number}"
   echo "Logs from stack:"
-  $SO_COMMAND deployment --dir $test_deployment_dir logs
+  $SO_COMMAND --stack fixturenet-eth deploy logs
   test_result=1
 fi
 $SO_COMMAND deployment --dir $test_deployment_dir stop --delete-volumes