“watch” command not displaying “tree” command output with Unicode bars and dashes

When executing

watch tree .

I get output as follows

Every 2.0s: tree .                                   macbook.local: Fri Dec 20 16:23:33 2019

.
    hello.txt
    hi.txt
    hmm.c
    subdir
        hello.txt

1 directory, 4 files

I want it to look like regular tree command output. Like below:

.
├── hello.txt
├── hi.txt
├── hmm.c
└── subdir
    └── hello.txt

1 directory, 4 files

I know that, I can use

while; do; clear; tree .; sleep 2; done

But I want to achieve the same thing with watch command