diff --git a/package-lock.json b/package-lock.json
index 04f8039..5435c41 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,7 +13,7 @@
         "@x-govuk/govuk-eleventy-plugin": "^6.4.2",
         "http-server": "^14.1.1",
         "rimraf": "^6.0.0",
-        "sass": "^1.80.5"
+        "sass": "^1.81.1"
       },
       "devDependencies": {
         "standard": "^17.1.0",
@@ -598,6 +598,7 @@
       "resolved": "https://registry.npmjs.org/@parcel/watcher/-/watcher-2.4.1.tgz",
       "integrity": "sha512-HNjmfLQEVRZmHRET336f20H/8kOozUGwk7yajvsonjNxbj2wBTK1WsQuHkD5yYh9RxFGL2EyDHryOihOwUoKDA==",
       "license": "MIT",
+      "optional": true,
       "dependencies": {
         "detect-libc": "^1.0.3",
         "is-glob": "^4.0.3",
@@ -2551,6 +2552,7 @@
       "resolved": "https://registry.npmjs.org/detect-libc/-/detect-libc-1.0.3.tgz",
       "integrity": "sha512-pGjwhsmsp4kL2RTz08wcOlGN83otlqHeD/Z5T8GXZB+/YcpQ/dgo+lbU8ZsGxV0HIvqqxo9l7mqYwyYMD9bKDg==",
       "license": "Apache-2.0",
+      "optional": true,
       "bin": {
         "detect-libc": "bin/detect-libc.js"
       },
@@ -4612,9 +4614,9 @@
       }
     },
     "node_modules/immutable": {
-      "version": "4.3.7",
-      "resolved": "https://registry.npmjs.org/immutable/-/immutable-4.3.7.tgz",
-      "integrity": "sha512-1hqclzwYwjRDFLjcFxOM5AYkkG0rpFPpr1RLPMEuGczoS7YA8gLhy8SWXYRAA/XwfEHpfo3cw5JGioS32fnMRw==",
+      "version": "5.0.3",
+      "resolved": "https://registry.npmjs.org/immutable/-/immutable-5.0.3.tgz",
+      "integrity": "sha512-P8IdPQHq3lA1xVeBRi5VPqUm5HDgKnx0Ru51wZz5mjxHr5n3RWhjIpOFU7ybkUxfB+5IToy+OLaHYDBIWsv+uw==",
       "license": "MIT"
     },
     "node_modules/import-fresh": {
@@ -6025,7 +6027,8 @@
       "version": "7.1.1",
       "resolved": "https://registry.npmjs.org/node-addon-api/-/node-addon-api-7.1.1.tgz",
       "integrity": "sha512-5m3bsyrjFWE1xf7nz7YXdN4udnVtXK6/Yfgn5qnahL6bCkf2yKt4k3nuTKAtT4r3IG8JNR2ncsIMdZuAzJjHQQ==",
-      "license": "MIT"
+      "license": "MIT",
+      "optional": true
     },
     "node_modules/node-retrieve-globals": {
       "version": "6.0.0",
@@ -7440,13 +7443,13 @@
       "license": "MIT"
     },
     "node_modules/sass": {
-      "version": "1.80.5",
-      "resolved": "https://registry.npmjs.org/sass/-/sass-1.80.5.tgz",
-      "integrity": "sha512-TQd2aoQl/+zsxRMEDSxVdpPIqeq9UFc6pr7PzkugiTx3VYCFPUaa3P4RrBQsqok4PO200Vkz0vXQBNlg7W907g==",
+      "version": "1.81.1",
+      "resolved": "https://registry.npmjs.org/sass/-/sass-1.81.1.tgz",
+      "integrity": "sha512-VNLgf4FC5yFyKwAumAAwwNh8X4SevlVREq3Y8aDZIkm0lI/zO1feycMXQ4hn+eB6FVhRbleSQ1Yb/q8juSldTA==",
+      "license": "MIT",
       "dependencies": {
-        "@parcel/watcher": "^2.4.1",
         "chokidar": "^4.0.0",
-        "immutable": "^4.0.0",
+        "immutable": "^5.0.2",
         "source-map-js": ">=0.6.2 <2.0.0"
       },
       "bin": {
@@ -7454,6 +7457,9 @@
       },
       "engines": {
         "node": ">=14.0.0"
+      },
+      "optionalDependencies": {
+        "@parcel/watcher": "^2.4.1"
       }
     },
     "node_modules/sass/node_modules/chokidar": {
diff --git a/package.json b/package.json
index 4279cea..5db3bec 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
     "@x-govuk/govuk-eleventy-plugin": "^6.4.2",
     "http-server": "^14.1.1",
     "rimraf": "^6.0.0",
-    "sass": "^1.80.5"
+    "sass": "^1.81.1"
   },
   "devDependencies": {
     "standard": "^17.1.0",