diff --git a/package.json b/package.json
index 4e71943..052b448 100644
--- a/package.json
+++ b/package.json
@@ -51,8 +51,8 @@
   "devDependencies": {
     "nyc": "^15.0.0",
     "chai": "^4.1.2",
-    "cssnano": "^4.0.0",
-    "cssnano-preset-advanced": "^4.0.0",
+    "cssnano": "^5.0.0",
+    "cssnano-preset-advanced": "^5.0.0",
  
     "postcss-cli": "^8.0.0",