diff --git a/lib/mining/template.js b/lib/mining/template.js
index 57bd8033d..eaa475abc 100644
--- a/lib/mining/template.js
+++ b/lib/mining/template.js
@@ -654,7 +654,7 @@ class BlockEntry {
     item.fee = entry.getFee();
     item.rate = entry.getDeltaRate();
     item.priority = entry.getPriority(attempt.height);
-    item.free = entry.getDeltaFee() < policy.getMinFee(entry.size);
+    item.free = entry.descFee < policy.getMinFee(entry.descSize);
     item.sigops = entry.sigops;
     item.descRate = entry.getDescRate();
     return item;
diff --git a/test/miner-test.js b/test/miner-test.js
index 40afc8aa0..d7e6a98e9 100644
--- a/test/miner-test.js
+++ b/test/miner-test.js
@@ -9,6 +9,7 @@ const Mempool = require('../lib/mempool/mempool');
 const Miner = require('../lib/mining/miner');
 const Address = require('../lib/primitives/address');
 const MTX = require('../lib/primitives/mtx');
+const Coin = require('../lib/primitives/coin');
 const MemWallet = require('./util/memwallet');
 const {BufferSet} = require('buffer-map');
 
@@ -77,6 +78,7 @@ describe('Miner', function() {
 
   let walletAddr;
   const txids = new BufferSet();
+  let coin, parentTX;
 
   it('should generate 20 blocks to wallet address', async () => {
     walletAddr = wallet.createReceive().getAddress();
@@ -110,7 +112,6 @@ describe('Miner', function() {
     }
 
     assert.strictEqual(mempool.map.size, 10);
-
     const block = await miner.mineBlock(chain.tip, addr);
     await chain.add(block);
 
@@ -180,4 +181,81 @@ describe('Miner', function() {
       assert(txids.has(block.txs[i].hash()));
     }
   });
+
+   it('should not include free transaction in a block', async () => {
+    // Miner does not have any room for free TXs
+    miner.options.minWeight = 0;
+
+    const value = 1 * 1e6;
+    const fee = 0;
+
+    // Get a change address
+    const change = wallet.createChange().getAddress();
+    const mtx = new MTX();
+    coin = wallet.getCoins()[0];
+    mtx.addCoin(coin);
+    mtx.addOutput(addr, value);
+    mtx.addOutput(change, coin.value - value - fee); // no fee
+    wallet.sign(mtx);
+    parentTX = mtx.toTX();
+
+    await mempool.addTX(parentTX, -1);
+    assert.strictEqual(mempool.map.size, 1);
+
+    const block = await miner.mineBlock(chain.tip, addr);
+    await chain.add(block);
+
+    // TX is still in mempool, nothing in block except coinbase
+    assert.strictEqual(mempool.map.size, 1);
+    assert.strictEqual(block.txs.length, 1);
+  });
+
+  it('should fail to double spend the coin - duplicate tx in mempool', async () => {
+    const value = 1 * 1e6;
+    const fee = 1000;
+    const mtx = new MTX();
+
+    const change = wallet.createChange().getAddress();
+    mtx.addCoin(coin);
+    mtx.addOutput(addr, value);
+    mtx.addOutput(change, coin.value - value - fee);
+    wallet.sign(mtx);
+    const tx = mtx.toTX();
+
+    assert.rejects(
+      async () => await mempool.addTX(tx, -1),
+      {
+        code: 'duplicate',
+        reason: 'bad-txns-inputs-spent'
+      }
+    );
+    // orignal tx is still in mempool
+    assert.strictEqual(mempool.map.size, 1);
+  });
+
+  it('should include child transaction if child pays enough fee (CPFP)', async () => {
+    const fee = 1000;
+
+    // Fee should be enough for both the first transation and second transaction
+    assert(fee > 140 + 108);
+
+    const mtx = new MTX();
+    const change = wallet.createChange().getAddress();
+    const coin = Coin.fromTX(parentTX, 1, -1);
+
+    mtx.addCoin(coin);
+    mtx.addOutput(change, coin.value - fee);
+    wallet.sign(mtx);
+    const tx = mtx.toTX();
+    await mempool.addTX(tx, -1);
+    // Both transactions in mempool
+    assert.strictEqual(mempool.map.size, 2);
+
+    const block = await miner.mineBlock(chain.tip, addr);
+    await chain.add(block);
+
+    // Both transactions should get mined into the block
+    assert.strictEqual(mempool.map.size, 0);
+    assert.strictEqual(block.txs.length, 3);
+  });
 });