diff --git a/package-lock.json b/package-lock.json
index 79e25694..181e37fc 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -2079,20 +2079,12 @@
       }
     },
     "clean-css": {
-      "version": "4.1.9",
-      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.1.9.tgz",
-      "integrity": "sha1-Nc7ornaHpJuYA09w3gDE7dOCYwE=",
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.2.1.tgz",
+      "integrity": "sha512-4ZxI6dy4lrY6FHzfiy1aEOXgu4LIsW2MhwG0VBKdcoGoH/XLFgaHSdLTGr4O8Be6A8r3MOphEiI8Gc1n0ecf3g==",
       "dev": true,
       "requires": {
-        "source-map": "0.5.x"
-      },
-      "dependencies": {
-        "source-map": {
-          "version": "0.5.7",
-          "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
-          "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=",
-          "dev": true
-        }
+        "source-map": "~0.6.0"
       }
     },
     "cliui": {
@@ -6075,6 +6067,23 @@
         "uglify-js": "3.3.x"
       },
       "dependencies": {
+        "clean-css": {
+          "version": "4.1.11",
+          "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-4.1.11.tgz",
+          "integrity": "sha1-Ls3xRaujj1R0DybO/Q/z4D4SXWo=",
+          "dev": true,
+          "requires": {
+            "source-map": "0.5.x"
+          },
+          "dependencies": {
+            "source-map": {
+              "version": "0.5.7",
+              "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.5.7.tgz",
+              "integrity": "sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=",
+              "dev": true
+            }
+          }
+        },
         "uglify-js": {
           "version": "3.3.12",
           "resolved": "https://registry.npmjs.org/uglify-js/-/uglify-js-3.3.12.tgz",
diff --git a/yarn.lock b/yarn.lock
index 6e72dea9..fa9b0607 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1450,8 +1450,8 @@ class-utils@^0.3.5:
     static-extend "^0.1.1"
 
 clean-css@4.1.x, clean-css@^4.1.3:
-  version "4.1.9"
-  resolved "https://registry.yarnpkg.com/clean-css/-/clean-css-4.1.9.tgz#35cee8ae7687a49b98034f70de00c4edd3826301"
+  version "4.1.11"
+  resolved "https://registry.yarnpkg.com/clean-css/-/clean-css-4.1.11.tgz#2ecdf145aba38f54740f26cefd0ff3e03e125d6a"
   dependencies:
     source-map "0.5.x"