celshading doesnt work on water in vibrant shaders

[retr0scape]

in the vibrant shaders the edges of water are not celshaded, they lack a black outline. however, the same issue is not present in the basic shaders or enhanced default shaders.

the first image is the vibrant shaders, the second is enhanced default.

i know its a bit hard to even notice but it bothers me, especially when i change the thickness of the outline.