# Invalid eventSourceArn

**URL:** <https://forum.serverless.com/t/invalid-eventsourcearn/4848>\
**Category:** Serverless Framework\
**Tags:** lambda\
**Created:** [June 22, 2018, 8:43pm UTC](https://forum.serverless.com/t/invalid-eventsourcearn/4848 "2018-06-22T20:43:29Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![billmcknight](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.serverless.com/billmcknight/32/2132_2.png) [@billmcknight](https://forum.serverless.com/u/billmcknight)\
**Post date:** [June 22, 2018, 8:43pm UTC](https://forum.serverless.com/t/invalid-eventsourcearn/4848/1 "2018-06-22T20:43:29Z")

</div>

I am attempting to a set up a lambda with an event source of a specific kinesis stream. The relevant section of my serverless.yml reads:

```
functions:
  dispatch-message:
    handler: bin/main
    events:
      - stream:
          arn: "arn:aws:kinesis:${opt:region, self:provider.region}:*:stream/${self:custom.ingestStream}"
          batchSize: 100
          startingPosition: LATEST
          enabled: true

```

When deployed, however, the stack operation fails with the error:

> An error occurred: DispatchDashmessageEventSourceMappingKinesisMessageingeststream - 1 validation error detected: Value 'arn:aws:kinesis:us-east-2:_:stream/message-ingest-stream’ at ‘eventSourceArn’ failed to satisfy constraint: Member must satisfy regular expression pattern: arn:(aws[a-zA-Z0-9-]_):([a-zA-Z0-9-])+:([a-z]{2}((-gov)|(-iso(b?)))?-[a-z]±\d{1})?:(\d{12})?:(.\*) (Service: AWSLambda; Status Code: 400; Error Code: ValidationException; Request ID: dabd0940-7646-11e8-ab0a-010e891e2d26).

This pattern of course works for other ARN specifications, for example specifying iam role statements resources. Is there a right way to specify the event source ARN without including the AccountId?.