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 July 1, 2010 (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 5.55% Series P Senior Notes due November 15, 2014 (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:

SECTION 1.01. Defined Terms. Terms defined in the Indenture and used herein without definition shall have the meanings assigned to them in the Indenture.

SECTION 2.01. Representations of the Company. The Company represents and warrants to the Trustee as follows:

(a) It is a corporation duly organized, validly existing and in good standing under the laws of the State of Texas.

(b) The execution, delivery and performance by it of this Supplemental Indenture have been authorized and approved by all necessary corporate action on its part.

SECTION 3.01. Assumptions and Agreements of Successor.

(a) In accordance with Section 1101 of the Indenture, the Company hereby expressly assumes 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.

(b) In accordance with Section 1102 of the Indenture, the Company 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 the Company had been named as the “Company” in the Indenture.

SECTION 4.01. Effectiveness of Supplemental Indenture. This Supplemental Indenture shall be effective upon its execution and delivery by the parties hereto.

SECTION 4.02. Governing Law. THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

SECTION 4.03. Full Force and Effect. Except as expressly supplemented hereby, the Indenture is in all respects ratified and confirmed and all the terms, conditions and provisions thereof shall remain in full force and effect. Upon the execution and delivery of this Supplemental Indenture by the Company and the Trustee, this Supplemental Indenture shall form a part of the Indenture for all purposes, and the Company, the Trustee and every Holder of Securities heretofore or hereafter authenticated and delivered shall be bound hereby. Any and all references to the Indenture, whether within the Indenture or in any notice, certificate or other instrument or document, shall be deemed to include a reference to this Supplemental Indenture (whether or not made), unless the context shall otherwise require.

SECTION 4.04. Indenture and Supplemental Indenture Construed Together. This Supplemental Indenture is an indenture supplemental to the Indenture, and the Indenture and this Supplemental Indenture shall henceforth be read and construed together.

SECTION 4.05. Confirmation and Preservation of Indenture. The Indenture as supplemented by this Supplemental Indenture is in all respects confirmed and preserved.

SECTION 4.06. Benefits of Supplemental Indenture. Nothing in this Supplemental Indenture, express or implied, shall give to any Person other than the parties hereto and thereto and their successors hereunder and thereunder and the Holders of the Securities, any benefit of any legal or equitable right, remedy or claim under the Indenture, this Supplemental Indenture or the Securities.

SECTION 4.07. Successors and Assigns. All covenants and agreements of the Company and the Trustee in this Supplemental Indenture shall bind their respective successors and assigns, whether so expressed or not.

SECTION 4.08. The Trustee. The Trustee shall not be responsible in any manner for or in respect of the validity or sufficiency of this Supplemental Indenture or for or in respect of the recitals contained herein, all of which are made by the Company.

SECTION 4.09. Counterparts. The parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an original, but all of them together represent the same agreement.

SECTION 4.10. Effect of Headings. The Section headings herein are for convenience only and shall not affect the construction hereof.

SECTION 4.11. Severability. If any provision in this Supplemental Indenture shall be invalid, illegal or unenforceable, the validity, legality or enforceability of the remaining provisions of this Supplemental Indenture or the Indenture shall not in any way be affected or impaired thereby.