"exports is not defined" error using gulp-babel

I have this error in the browser in the file that was compiled via gulp-babel.
The part from the gulp task is
.pipe(babel({
presets: ['@babel/preset-env'],
plugins: [
["@babel/plugin-transform-classes"]]
}))

Start with the gulp task configuration shown in the issue and reproduce the error from the browser-loaded compiled file. Inspect how the Babel preset and class-transform plugin affect the generated output; done means identifying the relevant configuration or compatibility issue and confirming that the compiled browser file no longer raises "exports is not defined".

Written by the indexing model from the issue text.