Fill the squares with the right tetrominoes

Fill the squares with the right tetrominoes, so each tetromino contains numbers 1 to 4.

Example :

I think this is a valid pattern:

I haven't used any particular strategy here. I just started in the top left corner continued where I could place an unambiguous tetromino. When I was stuck, I waited until I could approach the spot from the other side and resolve the ambiguity. I didn't really have to backtrack, maybe I corrected the previously placed tetromino two or three times.

In other words: I'm not going to write a detailed solution with all the steps. :)

I hope I haven't made any obvious blunders here.

• I got the same answer, except that I noticed that the top-right corner has a non-unique solution. The two tetrominoes (white/pink in your picture) can have their 1+2 squares exchanged. Mar 15 '17 at 9:46
• @JaapScherphuis Marius' answer actually shows the alternate there :) Mar 15 '17 at 9:49
• @JaapScherphuis I tried to make the puzzle have a single solution, but I was lazy to check it twice, and made a small mistake at the upper-right corner. Mar 15 '17 at 10:05

I think this works:
It took me a while to move everything to a google doc, because my image processing skills suck.

I tried to make the same form tetrominos the same color, but then I remembered that I'm color blind and forgot all the colors. Also it would get confusing when 2 shapes that are the same would be close to each other.

as a strategy, I started around (inside) the letters and marked the obvious ones. Then took it from there.