Okla. Stat. tit. 11, § 11-49-134: Mandatory retirement at age sixty-five - Exception

No person, who is eligible for retirement under the laws of this

state pertaining to the System, shall serve in any capacity as a

member of any fire department of any municipality of this state

after having attained the age of sixty-five (65) years, provided,

however, no person shall be required to retire because of the

provisions of this section until such person shall have completed

twenty (20) years service.