Abu Amir al-Hawzani (may Allah have mercy on him) said: I heard Sayyiduna Abu Ubaydah bin al-Jarrah (may Allah be pleased with him) when he was asked about making up Ramadan, and he said: Allah did not grant you the concession of not fasting in it while wanting to make things hard for you in making it up. Complete its number, and do as you wish.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8235