Okla. Stat. tit. 36, § 36-4015: Excluded or restricted coverage

A clause in any policy of life insurance providing that such

policy shall be incontestable after a specified period shall

preclude only a contest of the validity of the policy, and shall not

preclude the assertion at any time of defenses based upon provisions

in the policy which exclude or restrict coverage, whether or not

such restrictions or exclusions are excepted in such clause; nor

shall it be construed to preclude adjustment at any time of the

amount payable or benefits accruing under the policy for

misstatement of age, whether or not such age adjustment provision is

excepted in such clause.