diff --git a/lib/blockchain/migrations.js b/lib/blockchain/migrations.js
index 3edfef0f8..aab81dd95 100644
--- a/lib/blockchain/migrations.js
+++ b/lib/blockchain/migrations.js
@@ -351,6 +351,8 @@ class MigrateBlockStore extends AbstractMigration {
     this.ldb = options.ldb;
     this.blocks = options.db.blocks;
     this.layout = MigrateBlockStore.layout();
+
+    this.batchWriteSize = 10000;
   }
 
   /**
@@ -407,7 +409,7 @@ class MigrateBlockStore extends AbstractMigration {
       await this.blocks.writeBlock(hash, value);
       parent.del(key);
 
-      if (++total % 10000 === 0) {
+      if (++total % this.batchWriteSize === 0) {
         await parent.write();
         this.logger.debug('Migrated up %d blocks.', total);
         parent = this.ldb.batch();
@@ -441,7 +443,7 @@ class MigrateBlockStore extends AbstractMigration {
       await this.blocks.writeUndo(hash, value);
       parent.del(key);
 
-      if (++total % 10000 === 0) {
+      if (++total % this.batchWriteSize === 0) {
         await parent.write();
         this.logger.debug('Migrated up %d undo blocks.', total);
         parent = this.ldb.batch();
diff --git a/lib/wallet/txdb.js b/lib/wallet/txdb.js
index cd8043220..57b860251 100644
--- a/lib/wallet/txdb.js
+++ b/lib/wallet/txdb.js
@@ -1178,13 +1178,15 @@ class TXDB {
       // we need to add that information.
       // TODO: This can be skipped if TX is coinbase, but even now
       // it will be properly cleaned up on erase.
-      await this.addTimeAndCountIndexUnconfirmedUndo(b, hash);
+      await this.addTimeAndCountIndexUnconfirmedUndo(b, hash, wtx.mtime);
 
       await this.addBlockMap(b, height);
       await this.addBlock(b, tx.hash(), block);
     } else {
       // Add indexing for unconfirmed transactions.
-      await this.addCountAndTimeIndexUnconfirmed(b, state.accounts, hash);
+      await this.addCountAndTimeIndexUnconfirmed(b, state.accounts, hash,
+        wtx.mtime);
+
       await this.addTXMap(b, hash);
     }
 
@@ -1920,11 +1922,11 @@ class TXDB {
    * @private
    * @param {Batch} b
    * @param {Hash} hash - Transaction hash.
+   * @param {Number} time - Transaction time.
    * @returns {Promise}
    */
 
-  async addTimeAndCountIndexUnconfirmedUndo(b, hash) {
-    const time = this.nowFn();
+  async addTimeAndCountIndexUnconfirmedUndo(b, hash, time) {
     const count = await this.getLatestUnconfirmedTXCount();
 
     b.put(layout.e.encode(hash), fromU32(time));
@@ -1972,16 +1974,16 @@ class TXDB {
    * @param {Batch} b
    * @param {Map<Number, Balance>} accounts
    * @param {Hash} hash - Transaction hash.
+   * @param {Number} time - Transaction time.
    * @returns {Promise}
    */
 
-  async addCountAndTimeIndexUnconfirmed(b, accounts, hash) {
+  async addCountAndTimeIndexUnconfirmed(b, accounts, hash, time) {
     const count = await this.getLatestUnconfirmedTXCount();
 
     b.put(layout.z.encode(count.height, count.index), hash);
     b.put(layout.y.encode(hash), count.encode());
 
-    const time = this.nowFn();
     b.put(layout.e.encode(hash), fromU32(time));
     b.put(layout.w.encode(time, count.index, hash));
 
@@ -2121,11 +2123,11 @@ class TXDB {
     b.put(layout.y.encode(hash), count.encode());
 
     const time = blockextra.medianTime;
-    b.put(layout.g.encode(time, height, index, options.hash));
+    b.put(layout.g.encode(time, height, index, hash));
 
     for (const [acct] of accounts) {
       b.put(layout.Z.encode(acct, height, index), hash);
-      b.put(layout.G.encode(acct, time, height, index, options.hash));
+      b.put(layout.G.encode(acct, time, height, index, hash));
     }
   }
 
@@ -4628,7 +4630,7 @@ class BlockRecord extends bio.Struct {
   /**
    * Instantiate wallet block from serialized tip data.
    * @private
-   * @param {Buffer} data
+   * @param {bio.BufferReader} br
    */
 
   read(br) {
diff --git a/test/wallet-test.js b/test/wallet-test.js
index c1ffff563..48b77623d 100644
--- a/test/wallet-test.js
+++ b/test/wallet-test.js
@@ -3975,15 +3975,20 @@ describe('Wallet', function() {
       for (let i = 0; i < 2; i++) {
         for (const account of [DEFAULT, ALT]) {
           const mtx = await dummyTX(wallet, account);
-          // this increments/calls nowFn twice. One for
-          // wtx creation and another for unconfirmed index.
+          // this increments/calls nowFn once.
           await wdb.addTX(mtx.toTX());
           hashes.push(mtx.hash());
         }
       }
 
-      // zap will also call nowFn once. (0 - 3 time is incremented by first two)
-      const zapped = await wallet.zap(-1, time - 3);
+      // time will be 4 (4 txs), if we want to zap oldest 2 txs,
+      // zap will call nowFn once more, so time will be 5.
+      // First 2 txs have time 0 and 1. Zap accepts second argument
+      // age, which is time - age. So, we need to pass time - 1.
+      //  e.g. time - 1 = 4. Internal timer will be 5 (nowFn increment).
+      //  Age becomes: 5 - 4 = 1. So, zap will zap all txs with age 1
+      //  - so first 2 txs.
+      const zapped = await wallet.zap(-1, time - 1);
       assert.strictEqual(zapped.length, 2);
 
       const txsAfterZap = await wallet.listUnconfirmed(-1, {
@@ -4008,8 +4013,8 @@ describe('Wallet', function() {
         }
       }
 
-      // two transactions from default
-      const zapped = await wallet.zap(DEFAULT, time - 5);
+      // two transactions from default (calculation above.)
+      const zapped = await wallet.zap(DEFAULT, time - 3);
       assert.strictEqual(zapped.length, 2);
 
       const txsAfterZap = await wallet.listUnconfirmed(DEFAULT, {