13D Filing: Leucadia National and Lonestar Resources US Inc. (LONE)

This Amendment No. 1 amends the Statement on Schedule 13D first filed by Leucadia National Corporation
(Leucadia) on behalf of itself and its controlled subsidiaries (the Reporting Person) with the Securities and Exchange Commission on December 29, 2016 relating to the Class A Common Stock, par value
$0.001 per share (the Common Stock), of Lonestar Resources US Inc., a Delaware corporation (the Issuer). Capitalized terms used herein but not otherwise defined herein have the meanings given to them in the
Schedule 13D.

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

On June 12 and 13, 2017, Leucadia and JETX Energy, LLC (a controlled subsidiary of Leucadia formerly named Juneau Energy, LLC), entered into Voting and
Support Agreements and agreed with the Issuer to vote an aggregate of 3,978,488 shares of Common Stock in favor of the Issuers conversion of shares of Series A-2 Preferred Stock into Series A-1 Preferred Stock. The agreement to vote shares
excludes any shares of Common Stock that Leucadia or JETX Energy may dispose of or otherwise cease to have sole power to vote.

Item 7. Material
to be Filed as Exhibits.