diff --git a/src/ocean/Assets.ts b/src/ocean/Assets.ts
index 3cefca1b..69f0f3e9 100644
--- a/src/ocean/Assets.ts
+++ b/src/ocean/Assets.ts
@@ -70,18 +70,18 @@ export class Assets extends Instantiable {
     symbol?: string,
     providerUri?: string
   ): SubscribablePromise<CreateProgressStep, DDO> {
-    if (!isAddress(dtAddress)) {
+    if (dtAddress && !isAddress(dtAddress)) {
       this.logger.error(
         `Passed Data Token address ${dtAddress} is not valid. Aborting publishing.`
       )
       return null
     }
-
     this.logger.log('Creating asset')
     return new SubscribablePromise(async (observer) => {
       if (services.length === 0) {
         this.logger.log('You have no services. Are you sure about this?')
       }
+
       if (!dtAddress) {
         this.logger.log('Creating datatoken')
         observer.next(CreateProgressStep.CreatingDataToken)
@@ -394,7 +394,7 @@ export class Assets extends Instantiable {
   /**
    * Creates an access service
    * @param {Account} creator
-   * @param {String} cost  number of datatokens needed for this service, expressed in wei
+   * @param {String} cost  number of datatokens needed for this service
    * @param {String} datePublished
    * @param {Number} timeout
    * @return {Promise<string>} service
@@ -495,7 +495,7 @@ export class Assets extends Instantiable {
         await datatokens.balance(providerData.dataToken, consumerAddress)
       )
       const totalCost = new BigNumber(String(providerData.numTokens))
-      if (balance.isLessThanOrEqualTo(totalCost)) {
+      if (balance.isLessThan(totalCost)) {
         console.error(
           'Not enough funds. Needed ' +
             totalCost.toString() +
diff --git a/test/integration/Marketplaceflow.test.ts b/test/integration/Marketplaceflow.test.ts
index d84ee4b0..8a621b58 100644
--- a/test/integration/Marketplaceflow.test.ts
+++ b/test/integration/Marketplaceflow.test.ts
@@ -1,15 +1,15 @@
-import { AbiItem } from 'web3-utils/types'
+import datatokensTemplate from '@oceanprotocol/contracts/artifacts/DataTokenTemplate.json'
+import factory from '@oceanprotocol/contracts/artifacts/DTFactory.json'
 import { assert, spy, use } from 'chai'
 import spies from 'chai-spies'
-import { TestContractHandler } from '../TestContractHandler'
+import Web3 from 'web3'
+import { AbiItem } from 'web3-utils/types'
 import { DataTokens } from '../../src/datatokens/Datatokens'
+import { Account, EditableMetadata, ServiceAccess, ServiceCommon } from '../../src/lib'
 import { Ocean } from '../../src/ocean/Ocean'
 import { ConfigHelper } from '../../src/utils/ConfigHelper'
+import { TestContractHandler } from '../TestContractHandler'
 
-import Web3 from 'web3'
-import factory from '@oceanprotocol/contracts/artifacts/DTFactory.json'
-import datatokensTemplate from '@oceanprotocol/contracts/artifacts/DataTokenTemplate.json'
-import { Account, EditableMetadata, ServiceAccess, ServiceCommon } from '../../src/lib'
 const web3 = new Web3('http://127.0.0.1:8545')
 
 function sleep(ms: number) {
@@ -248,7 +248,7 @@ describe('Marketplace flow', () => {
       timeout
     )
 
-    spy.on(datatoken, 'create', () => null)
+    spy.on(ocean.datatokens, 'create', () => Promise.resolve(null))
     ddo = await ocean.assets.create(asset, alice, [service1])
     assert.equal(ddo, null)
   })