Musannaf Ibn Abi Shayba 3:2313

Abu Bakr narrated to us, he said: Yahya ibn Sa’id narrated to us, from Sa’id, from Qatadah, from Anas, that he missed a rak'ah, so he stood up and performed a voluntary prayer. Then he remembered, so he prayed the rak'ah that he had missed and prostrated two prostrations.