Al-Aswad, Alqamah and the companions of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrated: Sayyiduna Abdullah (may Allah be pleased with him) used to say regarding forgetfulness that a person should strive to determine what is correct, and perform two prostrations while sitting, after giving the salam.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9331