diff --git a/package.json b/package.json
index 8910f14..8078b3f 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
     "highlight.js": "~11.7",
     "js-yaml": "~4.1",
     "merge-stream": "~2.0",
-    "postcss-calc": "~8.2",
+    "postcss-calc": "~9.0",
     "postcss-custom-properties": "~13.1",
     "postcss-import": "~15.1",
     "postcss-url": "~10.1",