diff --git a/install/package.json b/install/package.json
index 25721c8289..ebcd4b3473 100644
--- a/install/package.json
+++ b/install/package.json
@@ -67,7 +67,7 @@
         "jsesc": "2.5.2",
         "json-2-csv": "^3.0.0",
         "jsonwebtoken": "^8.4.0",
-        "less": "^2.7.3",
+        "less": "^3.10.3",
         "lodash": "^4.17.15",
         "logrotate-stream": "^0.2.5",
         "lru-cache": "5.1.1",
diff --git a/src/meta/configs.js b/src/meta/configs.js
index 2568241163..30686ec8b2 100644
--- a/src/meta/configs.js
+++ b/src/meta/configs.js
@@ -119,6 +119,7 @@ function lessRender(string, callback) {
 	var less = require('less');
 	less.render(string, {
 		compress: true,
+		javascriptEnabled: true,
 	}, callback);
 }
 
diff --git a/src/meta/minifier.js b/src/meta/minifier.js
index 0024bbb9af..684b6864e4 100644
--- a/src/meta/minifier.js
+++ b/src/meta/minifier.js
@@ -268,6 +268,7 @@ Minifier.js.minifyBatch = function (scripts, fork, callback) {
 function buildCSS(data, callback) {
 	less.render(data.source, {
 		paths: data.paths,
+		javascriptEnabled: true,
 	}, function (err, lessOutput) {
 		if (err) {
 			return callback(err);
diff --git a/test/build.js b/test/build.js
index 0b40b28aa4..ca4c4ab866 100644
--- a/test/build.js
+++ b/test/build.js
@@ -183,7 +183,11 @@ describe('Build', function (done) {
 			var filename = path.join(__dirname, '../build/public/admin.css');
 			assert(file.existsSync(filename));
 			var adminCSS = fs.readFileSync(filename).toString();
-			assert(adminCSS.startsWith('@charset "UTF-8";') || adminCSS.startsWith('@import url'));
+			if (global.env === 'production') {
+				assert(adminCSS.startsWith('@charset "UTF-8";') || adminCSS.startsWith('@import url'));
+			} else {
+				assert(adminCSS.startsWith('.recent-replies'));
+			}
 			done();
 		});
 	});