diff --git a/src/utilities/content-tree-enhancers.mjs b/src/utilities/content-tree-enhancers.mjs
index 12f3ed24bed6..f65ea262fa38 100644
--- a/src/utilities/content-tree-enhancers.mjs
+++ b/src/utilities/content-tree-enhancers.mjs
@@ -144,7 +144,7 @@ export function restructure(item, options) {
   if (item.children) {
     for (const child of item.children) restructure(child, options);
 
-    item.children.filter(filter);
+    item.children = item.children.filter(filter);
     item.children.sort(sort);
   }
 
diff --git a/src/utilities/content-tree-enhancers.test.mjs b/src/utilities/content-tree-enhancers.test.mjs
new file mode 100644
index 000000000000..dfb7d12da696
--- /dev/null
+++ b/src/utilities/content-tree-enhancers.test.mjs
@@ -0,0 +1,57 @@
+// eslint-disable-next-line import/no-extraneous-dependencies
+import { describe, expect } from "@jest/globals";
+import { restructure } from "./content-tree-enhancers.mjs";
+
+describe("restructure", () => {
+  it("applies filter result back to children array", () => {
+    const originalChildren = [
+      {
+        type: "directory",
+        path: "src/content/guides",
+        title: "Guides",
+      },
+      {
+        type: "directory",
+        path: "src/content/api",
+        title: "API",
+      },
+    ];
+
+    const root = {
+      type: "directory",
+      path: "src/content",
+      children: originalChildren,
+    };
+
+    restructure(root, { dir: "src/content" });
+
+    // Filter creates a new array; restructure must assign that result back.
+    expect(root.children).not.toBe(originalChildren);
+    expect(root.children).toHaveLength(2);
+  });
+
+  it("sorts children after restructuring", () => {
+    const root = {
+      type: "directory",
+      path: "src/content",
+      children: [
+        {
+          type: "directory",
+          path: "src/content/guides",
+          title: "Guides",
+          sort: 20,
+        },
+        {
+          type: "directory",
+          path: "src/content/api",
+          title: "API",
+          sort: 10,
+        },
+      ],
+    };
+
+    restructure(root, { dir: "src/content" });
+
+    expect(root.children.map((item) => item.title)).toEqual(["API", "Guides"]);
+  });
+});