diff --git a/.github/workflows/validate-readme.yml b/.github/workflows/validate-readme.yml
new file mode 100644
index 0000000..7a1efe1
--- /dev/null
+++ b/.github/workflows/validate-readme.yml
@@ -0,0 +1,75 @@
+name: Validate README.md
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+    paths:
+      - "instructions/**"
+      - "prompts/**"
+      - "chatmodes/**"
+      - "*.js"
+
+jobs:
+  validate-readme:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+
+      - name: Update README.md
+        run: node update-readme.js
+
+      - name: Check for README.md changes
+        id: check-diff
+        run: |
+          if git diff --exit-code README.md; then
+            echo "No changes to README.md after running update script."
+            echo "status=success" >> $GITHUB_OUTPUT
+          else
+            echo "Changes detected in README.md after running update script."
+            echo "status=failure" >> $GITHUB_OUTPUT
+            echo "diff<<EOF" >> $GITHUB_OUTPUT
+            git diff README.md >> $GITHUB_OUTPUT
+            echo "EOF" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Comment on PR if README.md needs updating
+        if: steps.check-diff.outputs.status == 'failure'
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            const diff = `${{ steps.check-diff.outputs.diff }}`;
+            const body = `## ⚠️ README.md needs to be updated
+
+            The \`update-readme.js\` script detected changes that need to be made to the README.md file.
+
+            Please run \`node update-readme.js\` locally and commit the changes before merging this PR.
+
+            <details>
+              <summary>View diff</summary>
+              
+              \`\`\`diff
+              ${diff}
+              \`\`\`
+            </details>`;
+
+            github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+              body: body
+            });
+
+      - name: Fail workflow if README.md needs updating
+        if: steps.check-diff.outputs.status == 'failure'
+        run: |
+          echo "❌ README.md needs to be updated. Please run 'node update-readme.js' locally and commit the changes."
+          exit 1
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index adf3520..5c8ac13 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -61,6 +61,8 @@ Your goal is to...
 2. **Create a new branch** for your contribution
 3. **Add your instruction or prompt file** following the guidelines above
 4. **Run the update script** (optional): `node update-readme.js` to update the README with your new file
+   - A GitHub Actions workflow will verify that this step was performed correctly
+   - If the README.md would be modified by running the script, the PR check will fail with a comment showing the required changes
 5. **Submit a pull request** with:
    - A clear title describing your contribution
    - A brief description of what your instruction/prompt does