diff --git a/src/Transaction.js b/src/Transaction.js
index a4d5ba2..5323841 100644
--- a/src/Transaction.js
+++ b/src/Transaction.js
@@ -96,7 +96,7 @@ class Transaction {
    * @private
    */
   async _execute() {
-    await this.manager._mutex.acquire()
+    const mutexRelease = await this.manager._mutex.acquire()
     try {
       await this._prepare()
       await this._send()
@@ -105,7 +105,7 @@ class Transaction {
       this.manager._nonce = this.tx.nonce + 1
       return receipt
     } finally {
-      this.manager._mutex.release()
+      mutexRelease()
     }
   }
 
diff --git a/test/TxManager.test.js b/test/TxManager.test.js
index a8e461e..cd1224d 100644
--- a/test/TxManager.test.js
+++ b/test/TxManager.test.js
@@ -101,5 +101,23 @@ describe('TxManager', () => {
 
       console.log('receipt', receipt)
     })
+    it.only('should send multiple txs', async () => {
+      const genTx = value => ({
+        value,
+        to: '0x0039F22efB07A647557C7C5d17854CFD6D489eF3',
+      })
+      await Promise.all([
+        manager.createTx(genTx(1)).send(),
+        manager.createTx(genTx(2)).send(),
+        manager.createTx(genTx(3)).send(),
+        manager.createTx(genTx(4)).send(),
+        manager.createTx(genTx(5)).send(),
+        manager.createTx(genTx(6)).send(),
+        manager.createTx(genTx(7)).send(),
+        manager.createTx(genTx(8)).send(),
+        manager.createTx(genTx(9)).send(),
+        manager.createTx(genTx(10)).send(),
+      ])
+    })
   })
 })