diff --git a/package-lock.json b/package-lock.json
index 2d84f2de2..30a8739c6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2996,23 +2996,31 @@
       }
     },
     "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": "5.1.0",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.1.0.tgz",
+      "integrity": "sha512-98ALLW4NOhZpvUEoSc2dJO23xE4S4SXc4mLieCVFGo8DNLTFQ3gzi7msW1lqSYJeGZSF5r5+W3KF6cEnkILnFQ==",
       "dev": true,
       "requires": {
         "source-map": "~0.6.0"
       }
     },
     "clean-css-cli": {
-      "version": "4.3.0",
-      "resolved": "https://registry.npmjs.org/clean-css-cli/-/clean-css-cli-4.3.0.tgz",
-      "integrity": "sha512-8GHZfr+mG3zB/Lgqrr27qHBFsPSn0fyEI3f2rIZpxPxUbn2J6A8xyyeBRVTW8duDuXigN0s80vsXiXJOEFIO5Q==",
+      "version": "5.2.0",
+      "resolved": "https://registry.npmjs.org/clean-css-cli/-/clean-css-cli-5.2.0.tgz",
+      "integrity": "sha512-c7TQ+Lq8azYtThXtWlf0m9Iw66wBLQ0LPUJIEKHWTn8HB2tQlbqY6BMoKdgW4NJVZOYquwQrrRszTqH8NjHgTg==",
       "dev": true,
       "requires": {
-        "clean-css": "^4.2.1",
-        "commander": "2.x",
-        "glob": "7.x"
+        "clean-css": "^5.1.0",
+        "commander": "7.x",
+        "glob": "^7.1.6"
+      },
+      "dependencies": {
+        "commander": {
+          "version": "7.1.0",
+          "resolved": "https://registry.npmjs.org/commander/-/commander-7.1.0.tgz",
+          "integrity": "sha512-pRxBna3MJe6HKnBGsDyMv8ETbptw3axEdYHoqNh7gu5oDcew8fs0xnivZGm06Ogk8zGAJ9VX+OPEr2GXEQK4dg==",
+          "dev": true
+        }
       }
     },
     "clean-regexp": {
diff --git a/package.json b/package.json
index 48dd068ce..73d315a7d 100644
--- a/package.json
+++ b/package.json
@@ -138,7 +138,7 @@
     "autoprefixer": "^10.2.4",
     "browser-sync": "^2.26.14",
     "bundlewatch": "^0.3.2",
-    "clean-css-cli": "^4.3.0",
+    "clean-css-cli": "^5.2.0",
     "concurrently": "^5.3.0",
     "eslint": "^7.20.0",
     "eslint-config-xo": "^0.34.0",