где ошибка в gulp файле

при запуске gulp выдает такую ошибку в терминале

The following tasks did not complete: default, watch, server, styles Did you forget to signal async completion?

const browserSync = require('browser-sync');
const sass = require('gulp-sass')(require('sass'));
const cleanCSS = require('gulp-clean-css');
const autoprefixer = require('gulp-autoprefixer');
const rename = require("gulp-rename");


gulp.task('server', function () {

    browserSync({
        server: {
            baseDir: "src"
        }
    });

    gulp.watch("src/*.html").on('change', browserSync.reload);
});

gulp.task('styles', function () {
    return gulp.src("src/sass/**/*.+(scss|sass)")
        .pipe(sass({ outputStyle: 'compressed' }).on('error', sass.logError))
        .pipe(rename({ suffix: '.min', prefix: '' }))
        .pipe(autoprefixer())
        .pipe(cleanCSS({ compatibility: 'ie8' }))
        .pipe(gulp.dest("src/css"))
        .pipe(browserSync.stream());
});

gulp.task('watch', function () {
    gulp.watch("src/sass/**/*.+(scss|sass)", gulp.parallel('styles'));
})

gulp.task('default', gulp.parallel('watch', 'server', 'styles'));