diff --git a/packages/napcat-onebot/action/go-cqhttp/GetGroupFilesByFolder.ts b/packages/napcat-onebot/action/go-cqhttp/GetGroupFilesByFolder.ts
index 8fc45483..f8db4d2c 100644
--- a/packages/napcat-onebot/action/go-cqhttp/GetGroupFilesByFolder.ts
+++ b/packages/napcat-onebot/action/go-cqhttp/GetGroupFilesByFolder.ts
@@ -43,7 +43,8 @@ export class GetGroupFilesByFolder extends OneBotAction<PayloadType, ReturnType>
     return {
       files: ret.filter(item => item.fileInfo)
         .map(item => OB11Construct.file(item.peerId, item.fileInfo!)),
-      folders: [],
+      folders: ret.filter(item => item.folderInfo)
+        .map(item => OB11Construct.folder(item.peerId, item.folderInfo!)),
     };
   }
 }
diff --git a/packages/napcat-test/groupFilesByFolder.test.ts b/packages/napcat-test/groupFilesByFolder.test.ts
new file mode 100644
index 00000000..0072471c
--- /dev/null
+++ b/packages/napcat-test/groupFilesByFolder.test.ts
@@ -0,0 +1,67 @@
+// StreamBasic must be evaluated before OneBotAction: the two modules import each other,
+// and loading OneBotAction first leaves BasicStream extending an uninitialized binding.
+import '../napcat-onebot/action/stream/StreamBasic';
+import { describe, expect, test, vi } from 'vitest';
+import { GetGroupFilesByFolder } from '../napcat-onebot/action/go-cqhttp/GetGroupFilesByFolder';
+
+const FOLDER_ITEM = {
+  peerId: '123',
+  folderInfo: {
+    folderId: 'sub_folder_1',
+    folderName: '子目录',
+    createTime: 1,
+    createUin: '9',
+    creatorName: '创建者',
+    totalFileCount: 2,
+    modifyTime: 2,
+    modifyUin: '9',
+    modifyName: '修改者',
+  },
+};
+
+function createAction (items: unknown[]) {
+  const getGroupFileList = vi.fn().mockResolvedValue(items);
+  const action = new GetGroupFilesByFolder(
+    undefined as never,
+    {
+      apis: {
+        MsgApi: { getGroupFileList },
+      },
+    } as never
+  );
+  return { action, getGroupFileList };
+}
+
+describe('get_group_files_by_folder subfolders', () => {
+  test('maps folderInfo entries into folders', async () => {
+    const { action } = createAction([FOLDER_ITEM]);
+
+    const res = await action._handle({ group_id: '123', file_count: 50 });
+
+    expect(res.folders).toHaveLength(1);
+    expect(res.folders[0]).toMatchObject({
+      group_id: 123,
+      folder_id: 'sub_folder_1',
+      folder_name: '子目录',
+      total_file_count: 2,
+    });
+    expect(res.files).toHaveLength(0);
+  });
+
+  test('returns empty arrays when the folder holds nothing', async () => {
+    const { action } = createAction([]);
+
+    const res = await action._handle({ group_id: '123', file_count: 50 });
+
+    expect(res.files).toHaveLength(0);
+    expect(res.folders).toHaveLength(0);
+  });
+
+  test('passes the requested folder id through to the core API', async () => {
+    const { action, getGroupFileList } = createAction([]);
+
+    await action._handle({ group_id: '123', file_count: 50, folder_id: 'parent_1' });
+
+    expect(getGroupFileList).toHaveBeenCalledWith('123', expect.objectContaining({ folderId: 'parent_1' }));
+  });
+});