diff --git a/index.js b/index.js
index 85c6ddd..7d218a6 100644
--- a/index.js
+++ b/index.js
@@ -9,7 +9,10 @@ module.exports = function StaticSiteJson(folder, options = {}) {
   const cleanMarkdownFunnel = new BroccoliFunnel(folder, {
     include: ['**/*.md', '**/*.markdown'],
   });
-  const pagesTree = new TableOfContents([folder], options);
+  const tocFunnel = new BroccoliFunnel(folder, {
+    include: ['**/pages.yml', '**/pages.json'],
+  });
+  const pagesTree = new TableOfContents(tocFunnel, options);
   const jsonApiTree = new MarkdownToJsonApi(cleanMarkdownFunnel, options);
   const compiledTrees = new BroccoliMergeTrees([jsonApiTree, pagesTree]);
   return mv(compiledTrees, (options.contentFolder || 'content'));
diff --git a/lib/table-of-contents.js b/lib/table-of-contents.js
index d4da7bd..a35d4a9 100644
--- a/lib/table-of-contents.js
+++ b/lib/table-of-contents.js
@@ -1,3 +1,4 @@
+const PersistentFilter = require('broccoli-persistent-filter');
 const { Serializer } = require('jsonapi-serializer');
 const yaml = require('js-yaml');
 const { join } = require('path');
@@ -31,23 +32,30 @@ function subpageUrls(parentUrl, currentPage, childPages) {
   }
 }
 
-class TableOfContentsExtractor extends Plugin {
-  build() {
-    this.inputPaths.forEach((folder) => {
-      let pages;
-      if (existsSync(join(folder, 'pages.yml'))) {
-        pages = yaml.safeLoad(readFileSync(join(folder, 'pages.yml'), 'utf8'));
-      } else if (existsSync(join(folder, 'pages.json'))) {
-        // eslint-disable-next-line
-        pages = require(join(folder, 'pages.json'));
-      }
-      if (pages) {
-        // add the parent id to each subpage
-        subpageUrls(null, null, pages);
-
-        writeFileSync(join(this.outputPath, 'pages.json'), JSON.stringify(TableOfContentsSerializer.serialize(pages)));
-      }
-    });
+
+class TableOfContentsExtractor extends PersistentFilter {
+  constructor(folder, options) {
+    super(folder, options);
+    this.extensions = ['yml', 'json'];
+    this.targetExtension = 'json';
+  }
+
+  // eslint-disable-next-line class-methods-use-this,consistent-return
+  processString(content, relativePath) {
+    let pages;
+
+    if (relativePath.endsWith('pages.yml')) {
+      pages = yaml.safeLoad(content);
+    } else if (relativePath.endsWith('pages.json')) {
+      pages = JSON.parse(content);
+    }
+
+    if (pages) {
+      // add the parent id to each subpage
+      subpageUrls(null, null, pages);
+
+      return JSON.stringify(TableOfContentsSerializer.serialize(pages));
+    }
   }
 }
 
diff --git a/test/plugins/table-of-contents.js b/test/plugins/table-of-contents.js
index e05d477..6011d5e 100644
--- a/test/plugins/table-of-contents.js
+++ b/test/plugins/table-of-contents.js
@@ -8,8 +8,7 @@ describe('table-of-contents', function () {
   it('should build', async function () {
     const input = await createTempDir();
     try {
-      // TODO why does this need to be an array of folders
-      const subject = new TableOfContents([input.path()]);
+      const subject = new TableOfContents(input.path());
       const output = createBuilder(subject);
 
       try {