diff --git a/packages/shared/src/dto.ts b/packages/shared/src/dto.ts
index 56f3ff4..9872f16 100644
--- a/packages/shared/src/dto.ts
+++ b/packages/shared/src/dto.ts
@@ -86,6 +86,11 @@ export interface DriveTreeNode {
 
 export function sortDriveNodes(list: DriveTreeNode[]): DriveTreeNode[] {
   return [...list].sort((a, b) => {
+    if (a.modified_time !== b.modified_time) {
+      if (a.modified_time === null) return 1;
+      if (b.modified_time === null) return -1;
+      return b.modified_time - a.modified_time;
+    }
     if (a.is_folder !== b.is_folder) return a.is_folder ? -1 : 1;
     return a.name.localeCompare(b.name);
   });
diff --git a/packages/shared/test/dto.test.ts b/packages/shared/test/dto.test.ts
new file mode 100644
index 0000000..e4c1eba
--- /dev/null
+++ b/packages/shared/test/dto.test.ts
@@ -0,0 +1,50 @@
+import { describe, expect, it } from 'vitest';
+import { type DriveTreeNode, sortDriveNodes } from '../src/dto.js';
+
+function driveNode(id: string, modifiedTime: number | null, isFolder = false): DriveTreeNode {
+  return {
+    id,
+    name: id,
+    mime_type: isFolder ? 'application/vnd.google-apps.folder' : 'text/plain',
+    is_folder: isFolder,
+    modified_time: modifiedTime,
+    children: isFolder ? [] : null,
+  };
+}
+
+describe('sortDriveNodes', () => {
+  it('sorts files and folders from newest to oldest', () => {
+    const nodes = [
+      driveNode('old-folder', 100, true),
+      driveNode('new-file', 300),
+      driveNode('middle-file', 200),
+    ];
+
+    expect(sortDriveNodes(nodes).map((node) => node.id)).toEqual([
+      'new-file',
+      'middle-file',
+      'old-folder',
+    ]);
+  });
+
+  it('puts nodes without a modified time last', () => {
+    const nodes = [driveNode('unknown', null), driveNode('dated', 100)];
+
+    expect(sortDriveNodes(nodes).map((node) => node.id)).toEqual(['dated', 'unknown']);
+  });
+
+  it('uses folder and name tie-breakers without mutating the input', () => {
+    const nodes = [
+      driveNode('z-file', 100),
+      driveNode('b-folder', 100, true),
+      driveNode('a-folder', 100, true),
+    ];
+
+    expect(sortDriveNodes(nodes).map((node) => node.id)).toEqual([
+      'a-folder',
+      'b-folder',
+      'z-file',
+    ]);
+    expect(nodes.map((node) => node.id)).toEqual(['z-file', 'b-folder', 'a-folder']);
+  });
+});