diff --git a/History.md b/History.md
index 7d2dd59..58e5083 100644
--- a/History.md
+++ b/History.md
@@ -1,3 +1,8 @@
+[5.5.1 / 2022-xx-xx](https://github.com/clean-css/clean-css-cli/compare/v5.5.0...5.5)
+==================
+
+* Bumps clean-css dependency to 5.2.3.
+
 [5.5.0 / 2021-12-08](https://github.com/clean-css/clean-css-cli/compare/5.4...v5.5.0)
 ==================
 
diff --git a/package-lock.json b/package-lock.json
index 5317737..1f80c2d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -56,9 +56,9 @@
       }
     },
     "clean-css": {
-      "version": "5.2.2",
-      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.2.2.tgz",
-      "integrity": "sha512-/eR8ru5zyxKzpBLv9YZvMXgTSSQn7AdkMItMYynsFgGwTveCRVam9IUPFloE85B4vAIj05IuKmmEoV7/AQjT0w==",
+      "version": "5.2.3",
+      "resolved": "https://registry.npmjs.org/clean-css/-/clean-css-5.2.3.tgz",
+      "integrity": "sha512-qjywD7LvpZJ5+E16lf00GnMVUX5TEVBcKW1/vtGPgAerHwRwE4JP4p1Y40zbLnup2ZfWsd30P2bHdoAKH93XxA==",
       "requires": {
         "source-map": "~0.6.0"
       },
diff --git a/package.json b/package.json
index a6924ff..fcafa7d 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
   "homepage": "https://github.com/clean-css/clean-css-cli#readme",
   "dependencies": {
     "chokidar": "^3.5.2",
-    "clean-css": "^5.2.2",
+    "clean-css": "^5.2.3",
     "commander": "7.x",
     "glob": "^7.1.6"
   },