Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: When the prostration is at the end of the surah, then if you wish, go into bowing, and if you wish, go into prostration, for the prostration is together with the bowing.
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are thiqat (trustworthy).