AMENDMENT NO. 1 TO THE WILLIAM LYON HOMES 2012 EQUITY INCENTIVE PLAN

Exhibit 10.23(a)

AMENDMENT NO. 1

TO THE

WILLIAM LYON HOMES 2012 EQUITY INCENTIVE PLAN

This Amendment No. 1 (“Amendment”) to the William Lyon Homes 2012 Equity Incentive Plan (the “Plan”), is adopted by William Lyon Homes, a Delaware corporation (the “Company”), as of April 25, 2013.

RECITALS

A. Pursuant to Section 4.2 of the Plan, the Plan shall be administered by the Board of Directors (the “Board”) or the Compensation Committee (the “Committee”) as designated by the Board. Section 4.2 of the Plan further authorizes the Board, at any time and from time to time, to exercise any and all rights and duties of the Committee, subject to certain limitations.

B. Section 12.1 of the Plan provides that, among other things, the administrator may amend the Plan as it shall deem advisable, subject to any requirement for stockholder approval imposed by applicable law.

C. The Board desires to exercise its rights under Section 4.2 of the Plan to act as administrator and amend the Plan pursuant to the authority set forth under Section 12.1 of the Plan.

AMENDMENT

1. Subject to approval by the Company’s stockholders, Section 3.1(a) of the Plan is hereby amended and restated in its entirety to read as follows:

“(a) Subject to adjustment as provided in Section 12.2, a total of 30,000,000 Shares shall be authorized for issuance under the Plan.”

2. Capitalized terms used in this Amendment and not otherwise defined shall have the same meanings assigned to them in the Plan. Except as otherwise expressly set forth in this Amendment, the Plan shall remain in full force and effect in accordance with its terms.

3. This Amendment shall be governed by, interpreted under, and construed and enforced in accordance with the internal laws, and not the laws relating to conflicts or choice of laws, of the State of Delaware applicable to agreements made and to be performed wholly within the State of Delaware.

* * * * *

I hereby certify that this Amendment No. 1 was adopted by the Board of Directors on April 19, 2013 and by the stockholders of the Company on April 25, 2013.

Executed this 25th day of April, 2013.

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