@@ -13,4 +13,7 @@ export default [
   {
     file: 'routes/$.tsx',
   },
+  {
+    file: 'routes/main+/nested+/_index.tsx',
+  },
 ];
@@ -3,7 +3,7 @@ import os from 'node:os';
 import type { IsPluginEnabled, Plugin, ResolveConfig } from '../../types/config.js';
 import { _glob } from '../../util/glob.js';
 import { toEntry, toProductionDependency, toProductionEntry } from '../../util/input.js';
-import { join } from '../../util/path.js';
+import { isAbsolute, join, toAbsolute } from '../../util/path.js';
 import { hasDependency, load } from '../../util/plugin.js';
 import vite from '../vite/index.js';
 import type { PluginConfig, RouteConfigEntry } from './types.js';
@@ -23,7 +23,7 @@ const config = ['react-router.config.{js,ts}', ...viteConfig];
 const resolveConfig: ResolveConfig<PluginConfig> = async (localConfig, options) => {
   const { configFileDir } = options;
   const appDirectory = localConfig.appDirectory ?? 'app';
-  const appDir = join(configFileDir, appDirectory);
+  const appDir = toAbsolute(appDirectory, configFileDir);
 
   // If using flatRoutes from @react-router/fs-routes it will throw an error if this variable is not defined
   // @ts-expect-error
@@ -51,7 +51,7 @@ const resolveConfig: ResolveConfig<PluginConfig> = async (localConfig, options)
     // See:
     //  - https://reactrouter.com/how-to/file-route-conventions#optional-segments
     //  - https://www.npmjs.com/package/fast-glob#advanced-syntax
-    .map(route => (isWindows ? route : route.replace(/[\^*+?()[\]]/g, '\\$&')));
+    .map(route => (isWindows ? route : route.replace(/[\^*?()[\]]/g, '\\$&')));
 
   const resolved = [
     // routes.{ts,js} is only used as input to the bundler build system
 
@@ -15,8 +15,8 @@ test('Find dependencies with the react-router plugin', async () => {
 
   assert.deepEqual(counters, {
     ...baseCounters,
-    processed: 9,
-    total: 9,
+    processed: 10,
+    total: 10,
     // There is a bug with routes that include () on Windows so they will not be found there, revert when
     // the bug is fixed
     files: isWindows ? 1 : 0,
Original file line number	Diff line number	Diff line change
`@@ -13,4 +13,7 @@ export default [`
`13`	`13`	`{`
`14`	`14`	`file: 'routes/$.tsx',`
`15`	`15`	`},`
	`16`	`+ {`
	`17`	`+ file: 'routes/main+/nested+/_index.tsx',`
	`18`	`+ },`
`16`	`19`	`];`