diff --git a/gulpfile.js b/gulpfile.js
index 921907115e..330af7f768 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -2,11 +2,12 @@
 
 const gulp = require('gulp');
 const rename = require('gulp-rename');
+const sourcemaps = require('gulp-sourcemaps');
+const concat = require('gulp-concat-css');
 const postcss = require('gulp-postcss');
 const autoprefixer = require('autoprefixer');
 const cssnano = require('cssnano');
 const sorting = require('postcss-sorting');
-const concat = require('gulp-concat-css');
 const sortOrder = require('./.postcss-sorting.json');
 
 // Config
@@ -19,12 +20,14 @@ const paths = {
 
 function styles() {
 	return gulp.src(paths.styles.src)
+		.pipe(sourcemaps.init())
 		.pipe(
 			postcss([
 				autoprefixer(),
 				sorting(sortOrder),
-			])
+			]),
 		)
+		.pipe(sourcemaps.write('./'))
 		.pipe(gulp.dest(paths.styles.css));
 }
 
@@ -37,23 +40,26 @@ function minify() {
 		paths.styles.css + 'common.css',
 		paths.styles.css + 'buttons.css',
 		paths.styles.css + 'links.css',
+		paths.styles.css + 'mentions.css',
 		paths.styles.css + 'content.css',
 		paths.styles.css + 'cp.css',
 		paths.styles.css + 'forms.css',
 		paths.styles.css + 'colours.css',
 		paths.styles.css + 'responsive.css',
 		paths.styles.css + 'bidi.css',
-	], { sourcemaps: true })
+	])
+		.pipe(sourcemaps.init())
 		.pipe(concat('stylesheet.css'))
 		.pipe(
 			postcss([
 				cssnano(),
-			])
+			]),
 		)
 		.pipe(rename({
 			suffix: '.min',
 			extname: '.css',
 		}))
+		.pipe(sourcemaps.write('./'))
 		.pipe(gulp.dest(paths.styles.css));
 }