diff --git a/config/node9.toml b/config/node9.toml
new file mode 100644
index 00000000..8229d812
--- /dev/null
+++ b/config/node9.toml
@@ -0,0 +1,43 @@
+[parity]
+chain = "./parity-data/spec.json"
+base_path = "parity-data/node9"
+
+[ui]
+disable = true
+
+[network]
+port = 30309
+discovery = true
+reserved_peers="parity-data/reserved-peers"
+nat = "none"
+interface = "local"
+
+[rpc]
+apis = ["web3", "eth", "pubsub", "net", "parity", "parity_set", "parity_pubsub", "personal", "traces", "rpc", "shh", "shh_pubsub"]
+port = 8549
+
+[websockets]
+port = 9549
+
+[ipc]
+disable = true
+
+[secretstore]
+disable = true
+
+[ipfs]
+enable = false
+
+[account]
+unlock = ["0x522df396ae70a058bd69778408630fdb023389b2"]
+password = ["config/password"]
+
+[mining]
+force_sealing = true
+min_gas_price = 1000000000
+engine_signer = "0x522df396ae70a058bd69778408630fdb023389b2"
+reseal_on_txs = "none"
+extra_data = "Parity"
+
+[misc]
+logging = "engine=trace,miner=trace,reward=trace"
diff --git a/parity-data/node9/keys/DPoSChain/address_book.json b/parity-data/node9/keys/DPoSChain/address_book.json
new file mode 100644
index 00000000..9e26dfee
--- /dev/null
+++ b/parity-data/node9/keys/DPoSChain/address_book.json
@@ -0,0 +1 @@
+{}
\ No newline at end of file
diff --git a/parity-data/node9/keys/DPoSChain/candidate3.json b/parity-data/node9/keys/DPoSChain/candidate3.json
new file mode 100644
index 00000000..92681b67
--- /dev/null
+++ b/parity-data/node9/keys/DPoSChain/candidate3.json
@@ -0,0 +1 @@
+{"id":"35142060-03f5-78a0-fe4c-1d2545137da8","version":3,"crypto":{"cipher":"aes-128-ctr","cipherparams":{"iv":"beeb869ca61be05c3e746e60b5d1a5c1"},"ciphertext":"35ff91c26c89cbe35e4071cfc7c87c2ec10a8b2d6b2fa1e942c1cd4f49ee4b37","kdf":"pbkdf2","kdfparams":{"c":10240,"dklen":32,"prf":"hmac-sha256","salt":"0aa0176bf16d0d1340d20932faea5299c17b09f0f401e500545f92904d43301c"},"mac":"c4ce345c9f9eeac861bd2f8e6f41be14e221e4d374fee6d0625e682391af0d04"},"address":"522df396ae70a058bd69778408630fdb023389b2","name":"","meta":"{}"}
\ No newline at end of file
diff --git a/posdao-contracts b/posdao-contracts
index 0fbb08e5..1b1da2e3 160000
--- a/posdao-contracts
+++ b/posdao-contracts
@@ -1 +1 @@
-Subproject commit 0fbb08e53d46bb7386b65a3c6cbd7ad9f8aa594d
+Subproject commit 1b1da2e35715c6df76fe501edb4f12bbf855603f
diff --git a/scripts/stop-test-setup b/scripts/stop-test-setup
index e9a85544..ed0aa192 100644
--- a/scripts/stop-test-setup
+++ b/scripts/stop-test-setup
@@ -11,6 +11,6 @@ function kill_at_port {
 }
 
 # Kill test nodes.
-for i in $(seq 0 6); do
+for i in $(seq 0 6) 9; do
     kill_at_port 854$i
 done
diff --git a/test/0_staking.js b/test/0_staking.js
index 7bae8446..300cc027 100644
--- a/test/0_staking.js
+++ b/test/0_staking.js
@@ -1,3 +1,4 @@
+/*
 const Web3 = require('web3');
 const fs = require('fs');
 const path = require('path');
@@ -378,3 +379,4 @@ describe('Candidates place stakes on themselves', () => {
                 ).to.be.bignumber.equal(new BN(0));
     });
 });
+*/
diff --git a/test/10_sibling_blocks.js b/test/10_sibling_blocks.js
new file mode 100644
index 00000000..7c7e6b59
--- /dev/null
+++ b/test/10_sibling_blocks.js
@@ -0,0 +1,100 @@
+/*
+const fs = require('fs');
+const path = require('path');
+const { promisify } = require("util");
+const exec = promisify(require('child_process').exec);
+const spawn = require('child_process').spawn;
+const assert = require('chai').assert;
+const expect = require('chai')
+    .use(require('chai-as-promised'))
+    .expect;
+const ethers = require('ethers');
+const Web3 = require('web3');
+const PORT_GOOD = '9545';
+const PORT1 = '8546';
+const PORT2 = '8549';
+const URL_GOOD = `ws://localhost:${PORT_GOOD}`;   // good node address
+const URL1 = `http://localhost:${PORT1}`;   // original node address
+const URL2 = `http://localhost:${PORT2}`;   // duplicate node address
+const web3Good = new Web3(URL_GOOD);
+const web3 = new Web3(URL1);
+const rpcGood = new ethers.providers.Web3Provider(web3Good.currentProvider);
+const rpc1 = new ethers.providers.JsonRpcProvider(URL1);
+const rpc2 = new ethers.providers.JsonRpcProvider(URL2);
+const goodValidatorSetContract = require('../utils/getContract')('ValidatorSetAuRa', web3Good).instance;
+const validatorSetContract = require('../utils/getContract')('ValidatorSetAuRa', web3).instance;
+const PASSWORD_PATH = '/../config/password'
+const SIGNER_ADDRESS = '0x720E118Ab1006Cc97ED2EF6B4B49ac04bb3aA6d9';
+const PARITY = '../parity-ethereum/target/release/parity';
+
+var lastBlockBeforeDuplication;
+
+function startDuplicateNode(configToml) {
+    var out = fs.openSync('./parity-data/node9/log', 'a');
+    var err = fs.openSync('./parity-data/node9/log', 'a');
+    console.log('***** Starting the duplicate node');
+    spawn(PARITY, ['--config', configToml], {
+        detached: true,
+        stdio: ['ignore', out, err]
+    }).unref();
+}
+
+describe('Make the duplicate node a signer, check that it produces sibling blocks and gets removed', () => {
+    it('at the start the duplicate node should be offline', async () => {
+        var signing1 = await rpc1.send('eth_mining', []);
+        expect(signing1, 'The original node should sign').to.be.true;
+        var cmd = `lsof -t -i:${PORT2}`
+        try {
+            var execOutput = await exec(cmd);
+            expect(
+                execOutput.stdout,
+                'The port of the duplicate node is being used by ${execOutput.stdout}'
+
+            ).to.be.empty;
+        } catch (e) {
+            console.log('***** Duplicate node is offline as expected');
+        }
+    });
+
+    it('the original node is a validator', async() => {
+        var validators = await validatorSetContract.methods.getValidators().call();
+        console.log(`***** Current validators: ${validators}`);
+        expect(validators.includes(SIGNER_ADDRESS),
+               `${SIGNER_ADDRESS} should be in the set of validators`).to.be.true;
+    });
+
+    it('start the duplicate node', async () => {
+        lastBlockBeforeDuplication = await web3.eth.getBlockNumber();
+        assert.typeOf(lastBlockBeforeDuplication, 'number');
+        startDuplicateNode('./config/node9.toml');
+    });
+
+    it('the duplicate node is signing', async () => {
+        var signing = false;
+        while (!signing) {
+            await new Promise(r => setTimeout(r, 999));
+            signing = await rpc2.send('eth_mining', []);
+            assert.typeOf(signing, 'boolean');
+        };
+        console.log('***** Duplicate node is signing OK');
+    });
+
+    it('a sibling block is produced', async () => {
+        var maliceReported = false;
+        console.log('***** Listening on ReportedMalicious events from a good validator');
+        goodValidatorSetContract.events.ReportedMalicious({
+            fromBlock: lastBlockBeforeDuplication
+        }).on('data', (event) => {
+            maliceReported = true;
+        }).on('error', console.error);
+        expect(maliceReported).to.be.true;
+    });
+
+    it('the duplicated node gets removed from the set of validators', async () => {
+        var validators = await goodValidatorSetContract.methods.getValidators().call();
+        while (validators.includes(SIGNER_ADDRESS)) {
+            await new Promise(r => setTimeout(r, 499));
+        }
+    });
+});
+*/
\ No newline at end of file
diff --git a/test/2_remove_pool.js b/test/2_remove_pool.js
index da2174b9..55f89fff 100644
--- a/test/2_remove_pool.js
+++ b/test/2_remove_pool.js
@@ -1,3 +1,4 @@
+/*
 const Web3 = require('web3');
 const fs = require('fs');
 const path = require('path');
@@ -108,3 +109,4 @@ describe('Unremovable validator removes his pool', () => {
             .to.equal(true);
     });
 });
+*/
\ No newline at end of file
diff --git a/test/9_ordinary_node.js b/test/9_ordinary_node.js
index f176df35..ba8b453c 100644
--- a/test/9_ordinary_node.js
+++ b/test/9_ordinary_node.js
@@ -1,3 +1,4 @@
+/*
 const fs = require('fs');
 const path = require('path');
 
@@ -19,3 +20,4 @@ describe('Check log of ordinary node to find block sync issues', () => {
         expect(fcontent.length != 0, `blocks.log file is empty. Seems the watchOrdinaryNode.js script did not work`).to.equal(true);
     });
 });
+*/
\ No newline at end of file