Musnad Abu Ya'la al-Mawsili 150:18

Narrated to us Ishaq, narrated to us Sufyan, from al-Zuhri, from Abu Salamah, from Aisha, that the Messenger of Allah (may Allah bless him and grant him peace), when he intended to sleep while he was in a state of major ritual impurity (junub), he would perform ablution (wudu) like his ablution for prayer.