diff --git a/elm-book/package.json b/elm-book/package.json
index 60162a48..92a2cc6f 100644
--- a/elm-book/package.json
+++ b/elm-book/package.json
@@ -13,7 +13,7 @@
     "autoprefixer": "^10.4.2",
     "elm-review": "^2.8.2",
     "focus-visible": "^5.2.0",
-    "postcss": "^8.4.5",
+    "postcss": "^8.4.31",
     "postcss-focus-visible": "^6.0.3",
     "tailwindcss": "^3.0.15",
     "vite": "^2.9.16",
diff --git a/package.json b/package.json
index 21e6d3ce..58af723d 100644
--- a/package.json
+++ b/package.json
@@ -106,7 +106,7 @@
     "pdfjs-dist": "^2.7.570",
     "pdfmake": "^0.1.64",
     "phoenix": "^1.4.10",
-    "postcss": "^8.4.5",
+    "postcss": "^8.4.31",
     "postcss-cli": "^6.1.3",
     "postcss-focus-visible": "^6.0.1",
     "postcss-import": "^12.0.1",
diff --git a/yarn.lock b/yarn.lock
index 6e55b4e2..17b62a33 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2621,23 +2621,7 @@ chalk@^1.1.3:
     strip-ansi "^3.0.0"
     supports-color "^2.0.0"
 
-chalk@^4.0.0:
-  version "4.1.0"
-  resolved "https://registry.yarnpkg.com/chalk/-/chalk-4.1.0.tgz#4e14870a618d9e2edd97dd8345fd9d9dc315646a"
-  integrity sha512-qwx12AxXe2Q5xQ43Ac//I6v5aXTipYrSESdOgzrN+9XjgEpyjpKuvSGaN4qE93f7TQTlerQQ8S+EQ0EyDoVL1A==
-  dependencies:
-    ansi-styles "^4.1.0"
-    supports-color "^7.1.0"
-
-chalk@^4.1.0:
-  version "4.1.1"
-  resolved "https://registry.yarnpkg.com/chalk/-/chalk-4.1.1.tgz#c80b3fab28bf6371e6863325eee67e618b77e6ad"
-  integrity sha512-diHzdDKxcU+bAsUboHLPEDQiw0qEe0qd7SYUn3HgcFlWgbDcfLGswOHYeGrHKzG9z6UYf01d9VFMfZxPM1xZSg==
-  dependencies:
-    ansi-styles "^4.1.0"
-    supports-color "^7.1.0"
-
-chalk@^4.1.2:
+chalk@^4.0.0, chalk@^4.1.0, chalk@^4.1.2:
   version "4.1.2"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-4.1.2.tgz#aac4e2b7734a740867aeb16bf02aad556a1e7a01"
   integrity sha512-oKnbhFyRIXpUuez8iBMmyEa4nbj4IOQyuhc/wy9kY7/WVPcwIO9VA668Pu8RkO7+0G76SLROeyw9CpQ061i4mA==
@@ -10345,10 +10329,10 @@ postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.14, postcss@^7.0.26, postcss@^7.0.2
     picocolors "^0.2.1"
     source-map "^0.6.1"
 
-postcss@^8.1.6, postcss@^8.3.5, postcss@^8.4.13, postcss@^8.4.24, postcss@^8.4.5:
-  version "8.4.25"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.25.tgz#4a133f5e379eda7f61e906c3b1aaa9b81292726f"
-  integrity sha512-7taJ/8t2av0Z+sQEvNzCkpDynl0tX3uJMCODi6nT3PfASC7dYCWV9aQ+uiCf+KBD4SEFcu+GvJdGdwzQ6OSjCw==
+postcss@^8.1.6, postcss@^8.3.5, postcss@^8.4.13, postcss@^8.4.24, postcss@^8.4.31:
+  version "8.4.31"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.31.tgz#92b451050a9f914da6755af352bdc0192508656d"
+  integrity sha512-PS08Iboia9mts/2ygV3eLpY5ghnUcfLV/EXTOW1E2qYxJKGGBUtNjN76FYHnMs36RmARn41bC0AZmn+rR0OVpQ==
   dependencies:
     nanoid "^3.3.6"
     picocolors "^1.0.0"