diff --git a/package-lock.json b/package-lock.json
index 4c0fc37..283f93e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -556,9 +556,9 @@
       }
     },
     "clean-css": {
-      "version": "4.2.3",
-      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.2.3.tgz",
-      "integrity": "sha512-VcMWDN54ZN/DS+g58HYL5/n4Zrqe8vHJpGA8KdgUXFU4fuP/aHNw8eld9SyEIyabIMJX/0RaY/fplOo5hYLSFA==",
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.0.1.tgz",
+      "integrity": "sha512-F1zAGOowUCg8yxT0O4UR+nmbMauf3YwbiUS60CPxpzJU7ulpamGzQomFrJSK4w/HqHtMmQKSHJUNue+dQQYQdg==",
       "requires": {
         "source-map": "~0.6.0"
       }
diff --git a/package.json b/package.json
index 9b6f90b..59cc968 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
   },
   "dependencies": {
     "chalk": "^4.1.0",
-    "clean-css": "~4.2.3",
+    "clean-css": "~5.0.1",
     "maxmin": "^3.0.0"
   },
   "devDependencies": {
diff --git a/tasks/cssmin.js b/tasks/cssmin.js
index 5c37f4f..a86a3d4 100644
--- a/tasks/cssmin.js
+++ b/tasks/cssmin.js
@@ -29,7 +29,6 @@ module.exports = function (grunt) {
 
     this.files.forEach(function (file) {
       var options = this.options({
-        rebase: false,
         report: 'min',
         sourceMap: false
       });
@@ -37,7 +36,9 @@ module.exports = function (grunt) {
       var availableFiles = getAvailableFiles(file.src);
       var compiled = '';
 
-      options.rebaseTo = path.dirname(file.dest);
+      if (Boolean(options.rebase)) {
+        options.rebaseTo = path.dirname(file.dest);
+      }
 
       try {
         compiled = new CleanCSS(options).minify(availableFiles);
diff --git a/test/expected/rebase.css b/test/expected/rebase.css
index 173bce8..1e5e90b 100644
--- a/test/expected/rebase.css
+++ b/test/expected/rebase.css
@@ -1 +1 @@
-body{background:url(../test/fixtures/test.jpg)}/*# sourceMappingURL=rebase.css.map */
+body{background:url('../test/fixtures/test.jpg')}/*# sourceMappingURL=rebase.css.map */