What does 2 Samuel 15:31 mean?

Someone told David, 'Ahithophel is helping Absalom.' David prayed, 'God, please turn Ahithophel's advice into nonsense.' 2 Samuel 15:31 - Modern Text Bible

(David hears that his trusted advisor has switched sides to help his rebellious son. He immediately asks God to ruin Ahithophel's influence, knowing how dangerous his counsel could be.)