No need to add two points.

When u is a single final, the standard tones are ǖ, ǘ, ǚ, ǜ, and there is no need to remove the two dots. Keeping two points avoids confusion with the letter u. When marking Chinese characters with pinyin, the syllables in characters such as "鱼" and "雨" are written as yu, and two points need to be removed when marking the intonation. "yū", "yú", "yǔ" and "yù". The u (yu) here is different from the real letter u (wu) to avoid ambiguity.