New King James Version
Let him not trust in futile things, deceiving himself, For futility will be his reward.

King James Bible
Let not him that is deceived trust in vanity: for vanity shall be his recompence.

American Standard Version
Let him not trust in vanity, deceiving himself; For vanity shall be his recompense.

Berean Study Bible
Let him not deceive himself with trust in emptiness, for emptiness will be his reward.

Douay-Rheims Bible
He shall not believe, being vainly deceived by error, that he may be redeemed with any price.

English Revised Version
Let him not trust in vanity, deceiving himself: for vanity shall be his recompence.

World English Bible
Let him not trust in emptiness, deceiving himself; for emptiness shall be his reward.

Young's Literal Translation
Let him not put credence in vanity, He hath been deceived, For vanity is his recompence.

Job 15:31 Additional Translations ...