It does indeed say so:
CCC: Part One, Section Two, Chapter Two, Article 3, Paragraph 1
460. The Word became flesh to make us "partakers of the divine nature":78 "For this is why the Word became man, and the Son of God became the Son of man: so that man, by entering into communion with the Word and thus receiving divine sonship, might become a son of God."79 "For the Son of God became man so that we might become God."80 "The only-begotten Son of God, wanting to make us sharers in his divinity, assumed our nature, so that he, made man, might make men gods."81
Footnote 81: St. Thomas Aquinas, Opusc. 57, 1-4.
I have not read much of St. Thomas Aquinas so I do not know what this references.