diff --git a/lib/mining/miner.js b/lib/mining/miner.js
index 55784355..c41650a3 100644
--- a/lib/mining/miner.js
+++ b/lib/mining/miner.js
@@ -449,8 +449,7 @@ Miner.prototype.build = function build(attempt) {
     }
   }
 
-  attempt.updateCoinbase();
-  attempt.updateMerkle();
+  attempt.refresh();
 
   assert(block.getWeight() <= attempt.weight);
 };
diff --git a/lib/mining/minerblock.js b/lib/mining/minerblock.js
index 222b9e70..030614da 100644
--- a/lib/mining/minerblock.js
+++ b/lib/mining/minerblock.js
@@ -172,11 +172,8 @@ MinerBlock.prototype._init = function _init() {
 
   block.txs.push(cb);
 
-  // Update coinbase since our coinbase was added.
-  this.updateCoinbase();
-
-  // Create our merkle root.
-  this.updateMerkle();
+  // Update commitments.
+  this.refresh();
 
   // Initialize weight.
   this.weight = this.block.getWeight();
@@ -188,6 +185,23 @@ MinerBlock.prototype._init = function _init() {
   this.sigops = cb.getSigopsCost(null, this.flags);
 };
 
+/**
+ * Update coinbase, witness
+ * commitment, and merkle root.
+ */
+
+MinerBlock.prototype.refresh = function refresh() {
+  // Update coinbase.
+  this.updateCoinbase();
+
+  // Witness commitment.
+  if (this.witness)
+    this.updateCommitment();
+
+  // Create our merkle root.
+  this.updateMerkle();
+};
+
 /**
  * Update the commitment output for segwit.
  */
@@ -226,8 +240,6 @@ MinerBlock.prototype.updateCoinbase = function updateCoinbase() {
  */
 
 MinerBlock.prototype.updateNonce = function updateNonce() {
-  this.block.ts = Math.max(this.network.now(), this.tip.ts + 1);
-
   // Overflow the nonce and increment the extraNonce.
   this.block.nonce = 0;
   this.nonce1++;
@@ -246,20 +258,10 @@ MinerBlock.prototype.updateNonce = function updateNonce() {
 };
 
 /**
- * Rebuild the merkle tree and update merkle root as well as the
- * timestamp (also calls {@link MinerBlock#updateCommitment}
- * if segwit is enabled).
+ * Rebuild the merkle tree and update merkle root.
  */
 
 MinerBlock.prototype.updateMerkle = function updateMerkle() {
-  // Always update commitment before updating merkle root.
-  // The updated commitment output will change the merkle root.
-  if (this.witness)
-    this.updateCommitment();
-
-  // Update timestamp.
-  this.block.ts = Math.max(this.network.now(), this.tip.ts + 1);
-
   // Recalculate merkle root.
   this.block.merkleRoot = this.block.createMerkleRoot('hex');
 };
@@ -315,11 +317,8 @@ MinerBlock.prototype.addTX = function addTX(tx, view) {
   this.block.txs.push(tx);
   this.items.push(item);
 
-  // Update coinbase value
-  this.updateCoinbase();
-
-  // Update merkle root for new coinbase and new tx
-  this.updateMerkle();
+  // Update commitments.
+  this.refresh();
 
   return true;
 };
@@ -400,8 +399,6 @@ MinerBlock.prototype.mine = function mine() {
   // Track how long we've been at it.
   this.begin = util.now();
 
-  assert(this.block.ts > this.tip.ts);
-
   for (;;) {
     nonce = this.findNonce();
 
@@ -427,8 +424,6 @@ MinerBlock.prototype.mineAsync = co(function* mineAsync() {
   // Track how long we've been at it.
   this.begin = util.now();
 
-  assert(this.block.ts > this.tip.ts);
-
   for (;;) {
     nonce = yield this.findNonceAsync();
 
@@ -451,28 +446,12 @@ MinerBlock.prototype.mineAsync = co(function* mineAsync() {
  */
 
 MinerBlock.prototype.iterate = function iterate() {
-  var block = this.block;
-  var tip = this.tip;
-  var now = this.network.now();
-
   // Keep track of our iterations.
   this.iterations++;
 
   // Send progress report.
   this.sendStatus();
 
-  // If we took more a second or more (likely),
-  // skip incrementing the extra nonce and just
-  // update the timestamp. This improves
-  // performance because we do not have to
-  // recalculate the merkle root.
-  if (now > block.ts && now > tip.ts) {
-    block.ts = now;
-    // Overflow the nonce
-    block.nonce = 0;
-    return;
-  }
-
   // Overflow the nonce and increment the extraNonce.
   this.updateNonce();
 };