diff --git a/.npmrc b/.npmrc
new file mode 100644
index 00000000..b6f27f13
--- /dev/null
+++ b/.npmrc
@@ -0,0 +1 @@
+engine-strict=true
diff --git a/.nvmrc b/.nvmrc
index f48de772..c12134be 100644
--- a/.nvmrc
+++ b/.nvmrc
@@ -1 +1 @@
-v20.4.0
\ No newline at end of file
+v20.15.0
diff --git a/README.md b/README.md
index 6d901568..89a2d061 100755
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ A place to learn and share with developers what makes web work accessible. This
 
 - nvm: A Node version manager. It allows you to install several versions of node on the same machine and change versions easily.
   - [Here are instructions in how to install nvm](https://github.com/nvm-sh/nvm#usage)
-  - After installing nvm, install a Node version >= 18 using nvm, ideally `nvm install 20.11.0`
+  - After installing nvm, install a Node version >= 20.15.0 using nvm, ideally `nvm install 20.15.0`
 - npm: a Node Package Manager, usually installed alongside Node
   - More info: [Downloading and installing Node.js and NPM](https://docs.npmjs.com/downloading-and-installing-node-js-and-npm)
 - Lynx: A text-only browser used for testing for how a website will work without graphics turned on.
diff --git a/package.json b/package.json
index fd798a21..6ec3165c 100644
--- a/package.json
+++ b/package.json
@@ -142,6 +142,10 @@
     "text-zoom-event": "^1.7.0",
     "wicg-inert": "^3.1.2"
   },
+  "engines": {
+    "npm": ">=10.7.0 <=10.8.1",
+    "node": ">=20.15.0 <=20.16.0"
+  },
   "bin": {
     "enable-a11y": "bin/server.js"
   },