SECOND SUPPLEMENTAL INDENTURE

Second Supplemental Indenture (this “Supplemental Indenture”), dated as of April 15, 2013, between Energy Future Holdings Corp. (formerly EFH2 Corp.), a Texas corporation (the “Company”), and The Bank of New York Mellon Trust Company, N.A., a national banking association (successor as trustee to The Bank of New York Mellon (formerly known as The Bank of New York), a New York banking corporation), as Trustee (the “Trustee”).

WHEREAS, Energy Future Holdings Corp. (formerly TXU Corp.), a Texas corporation (the “Predecessor”), has heretofore executed and delivered to the Trustee an Indenture, dated as of November 1, 2004, as supplemented and amended by the Supplemental Indenture, dated as of December 5, 2012 (as so supplemented and amended, the “Indenture”), and an Officer's Certificate, dated as of November 26, 2004, providing for the issuance of the Predecessor's 6.55% Series R Senior Notes due November 15, 2034 (the “Securities”);

WHEREAS, the Predecessor has contributed all of the capital stock of Energy Future Competitive Holdings Company to the Company, which contribution did not constitute the transfer of all or substantially all of the properties or assets of the Predecessor;

WHEREAS, on the date hereof, simultaneously with the effectiveness of this Supplemental Indenture, the Predecessor shall have merged with and into the Company, with the Company continuing its existence under the laws of the State of Texas, and the merger shall have become effective under the laws of the State of Texas;

WHEREAS, Section 1101 of the Indenture provides that the Predecessor shall not merge into any other corporation, in a transaction in which the Predecessor is not the successor corporation, unless, among other things, the corporation into which the Predecessor is merged expressly assumes, by an indenture supplemental to the Indenture, executed and delivered to the Trustee, in form satisfactory to the Trustee, the due and punctual payment of the principal of and premium, if any, and interest, if any, on all Outstanding Securities and the performance of every covenant of the Indenture on the part of the Predecessor to be performed or observed;

WHEREAS, Section 1102 of the Indenture provides that, upon any merger by the Predecessor into any other corporation in accordance with Section 1101, the successor corporation into which the Predecessor is merged shall succeed to, and be substituted for, and may exercise every right and power of, the Predecessor under the Indenture with the same effect as if such successor Person had been named as the “Company” in the Indenture;

WHEREAS, Section 1201 of the Indenture provides that, without the consent of any Holders, the Company and the Trustee may, at any time and from time to time, enter into one or more indentures supplemental to the Indenture, in form satisfactory to the Trustee, to evidence the succession of another Person to the Predecessor and the assumption by any such successor of the covenants of the Predecessor in the Indenture and the Securities, all as provided in Article Eleven of the Indenture;

WHEREAS, the Company desires and has requested that the Trustee join in execution of this Supplemental Indenture for the purpose of evidencing such succession and assumption;

WHEREAS, the Company has been duly authorized to enter into this Supplemental Indenture;

WHEREAS, all conditions necessary to authorize the execution and delivery of this Supplemental Indenture and to make this Supplemental Indenture a valid and binding instrument enforceable in accordance with its terms have been complied with or have been done or performed; and

WHEREAS, pursuant to Section 1201 of the Indenture, the Trustee is authorized to execute and deliver this Supplemental Indenture.

NOW THEREFORE, in consideration of the foregoing and for other good and valuable consideration, the receipt of which is hereby acknowledged, the parties mutually covenant and agree for the equal and ratable benefit of the Holders of the Securities as follows: