The change was first spotted by @ec_wife on Twitter, according to a report in The Next Web (TNW) on Friday.
Facebook later confirmed the test to social media consultant Matt Navarra.
The social media network said that the feature will not transgress user privacy as Instagram users can choose not to have their Stories visible on Facebook.
Facebook CEO Mark Zuckerberg last year announced plans to integrate the messaging services of the company's family of apps.
For example, Instagram and Facebook Messenger recently began merging their chat functionalities. It is expected that WhatsApp will also eventually be part of the integration.
As part of the latest efforts to make it easier to share Instagram Stories, the platform is allowing users who are part of the test to know where the post was first shared.
(Only the headline and picture of this report may have been reworked by the Business Standard staff; the rest of the content is auto-generated from a syndicated feed.)