AMENDMENT TO THE BANCFIRST CORPORATION EMPLOYEE STOCK OWNERSHIP PLAN

Exhibit 10.9

AMENDMENT TO THE

BANCFIRST CORPORATION EMPLOYEE STOCK OWNERSHIP PLAN

TO COMPLY WITH

CODE SECTION 415 REGULATIONS

ARTICLE I

PREAMBLE

1.1 Authority to Amend. BancFirst Corporation (the “Employer”) pursuant to the terms of the BancFirst Corporation Employee Stock Ownership Plan (the “Plan”) hereby amends the Plan’s governing document (the “Plan Document”) pursuant to its authority as set forth in Section 10.1 of the Plan Document.

1.2 Purpose of Amendment. The purpose of this amendment is to cause the Plan to comply with Final Regulations published under section 415 of the Internal Revenue Code.

1.3 Effective date of Amendment. This Amendment is effective for Plan Years beginning after July 1, 2007.

1.4 Superseding of inconsistent provisions. This Amendment supersedes the provisions of the Plan to the extent those provisions are inconsistent with the provisions of this Amendment. Except as expressly set forth herein, the Plan Document is ratified in all respects.

ARTICLE II

FINAL SECTION 415 REGULATIONS

2.1 Effective date. The provisions of this Article II shall apply to limitation years beginning on and after July 1, 2007.

2.2 Actual Compensation paid after severance from employment. Actual Compensation shall be adjusted, as set forth herein, for the following types of compensation paid after a Participant’s severance from employment with the Employer maintaining the Plan (or any other entity that is treated as the Employer pursuant to Code § 414(b), (c), (m) or (o)). However, amounts described in subsections (a) and (b) below may only be included in Actual Compensation to the extent such amounts are paid by the later of 2  ¹ / 2 months after severance from employment or by the end of the limitation year that includes the date of such severance from employment. Any other payment of compensation paid after severance of employment that is not described in the following types of compensation is not considered Actual Compensation within the meaning of Code § 415(c)(3), even if payment is made within the time period specified above.

(1) The payment is regular compensation for services during the participant’s regular working hours, or compensation for services outside the participant’s regular working hours (such as overtime or shift differential), commissions, bonuses, or other similar payments; and

(2) The payment would have been paid to the participant prior to a severance from employment if the participant had continued in employment with the Employer.

2.3 Administrative delay (“the first few weeks”) rule. Actual Compensation for a limitation year shall not include amounts earned but not paid during the limitation year solely because of the timing of pay periods and pay dates.

2.4 Inclusion of certain nonqualified deferred compensation amounts. If the Plan’s definition of Compensation for purposes of Code § 415 is the definition in Regulation Section 1.415(c)-2(b) (Regulation Section 1.415-2(d)(2) under the Regulations in effect for limitation years beginning prior to July 1, 2007) and the simplified compensation definition of Regulation 1.415(c)-2(d)(2) (Regulation Section 1.415-2(d)(10) under the Regulations in effect for limitation years prior to July 1, 2007) is not used, then Actual Compensation shall include amounts that are includible in the gross income of a Participant under the rules of Code § 409A or Code § 457(f)(1)(A) or because the amounts are constructively received by the Participant.

2.5 Definition of annual additions. The Plan’s definition of “annual additions” is modified as follows: