diff --git a/src/Transaction.js b/src/Transaction.js
index e681ce8..def47d1 100644
--- a/src/Transaction.js
+++ b/src/Transaction.js
@@ -116,6 +116,11 @@ class Transaction {
    * @private
    */
   async _prepare() {
+    if (!this.config.BLOCK_GAS_LIMIT) {
+      const lastBlock = await this._provider.getBlock('latest')
+      this.config.BLOCK_GAS_LIMIT = lastBlock.gasLimit.toNumber()
+    }
+
     if (!this.tx.gasLimit || this.config.ESTIMATE_GAS) {
       const gas = await this._wallet.estimateGas(this.tx)
       if (!this.tx.gasLimit) {
diff --git a/src/TxManager.js b/src/TxManager.js
index 669d077..00a5198 100644
--- a/src/TxManager.js
+++ b/src/TxManager.js
@@ -35,11 +35,7 @@ class TxManager {
    *
    * @param tx Transaction to send
    */
-  async createTx(tx) {
-    if (!this.config.BLOCK_GAS_LIMIT) {
-      const lastBlock = await this._provider.getBlock('latest')
-      this.config.BLOCK_GAS_LIMIT = lastBlock.gasLimit.toNumber()
-    }
+  createTx(tx) {
     return new Transaction(tx, this)
   }
 }
diff --git a/test/TxManager.test.js b/test/TxManager.test.js
index 56890ff..a8e461e 100644
--- a/test/TxManager.test.js
+++ b/test/TxManager.test.js
@@ -10,7 +10,7 @@ describe('TxManager', () => {
     privateKey: PRIVATE_KEY,
     rpcUrl: RPC_URL,
     config: {
-      CONFIRMATIONS: 3,
+      CONFIRMATIONS: 1,
       GAS_BUMP_INTERVAL: 1000 * 15,
     },
   })
@@ -39,7 +39,7 @@ describe('TxManager', () => {
 
   describe('#transaction', () => {
     it('should work', async () => {
-      const tx = await manager.createTx(tx1)
+      const tx = manager.createTx(tx1)
 
       const receipt = await tx
         .send()
@@ -51,7 +51,7 @@ describe('TxManager', () => {
     })
 
     it('should fetch gas price', async () => {
-      const tx = await manager.createTx(tx4)
+      const tx = manager.createTx(tx4)
 
       const receipt = await tx
         .send()
@@ -63,7 +63,7 @@ describe('TxManager', () => {
     })
 
     it('should bump gas price', async () => {
-      const tx = await manager.createTx(tx2)
+      const tx = manager.createTx(tx2)
 
       const receipt = await tx
         .send()
@@ -75,7 +75,7 @@ describe('TxManager', () => {
     })
 
     it('should cancel', async () => {
-      const tx = await manager.createTx(tx2)
+      const tx = manager.createTx(tx2)
 
       setTimeout(() => tx.cancel(), 1000)
 
@@ -89,7 +89,7 @@ describe('TxManager', () => {
     })
 
     it('should replace', async () => {
-      const tx = await manager.createTx(tx2)
+      const tx = manager.createTx(tx2)
 
       setTimeout(() => tx.replace(tx3), 1000)