diff --git a/src/run.test.ts b/src/run.test.ts
new file mode 100644
index 00000000..2994a694
--- /dev/null
+++ b/src/run.test.ts
@@ -0,0 +1,16 @@
+import path from 'node:path';
+import fs from 'node:fs';
+import isThere from 'is-there';
+import { rimraf } from 'rimraf';
+import { run } from './run';
+
+describe(run, () => {
+  beforeEach(async () => {
+    await rimraf('example/style01.css.d.ts');
+  });
+
+  it('generates type definition files', async () => {
+    await run('example', { watch: false });
+    expect(isThere(path.normalize('example/style01.css.d.ts'))).toBeTruthy();
+  });
+});
diff --git a/src/run.ts b/src/run.ts
index 2856dd2b..44c24225 100644
--- a/src/run.ts
+++ b/src/run.ts
@@ -17,7 +17,7 @@ interface RunOptions {
 }
 
 export async function run(searchDir: string, options: RunOptions = {}): Promise<void> {
-  const filesPattern = path.join(searchDir, options.pattern || '**/*.css');
+  const filesPattern = searchDir.replace(/\\/g, '/') + '/' + (options.pattern || '**/*.css');
 
   const creator = new DtsCreator({
     rootDir: process.cwd(),
@@ -78,7 +78,7 @@ export async function run(searchDir: string, options: RunOptions = {}): Promise<
   } else {
     console.log('Watch ' + filesPattern + '...');
 
-    const watcher = chokidar.watch([filesPattern.replace(/\\/g, '/')]);
+    const watcher = chokidar.watch([filesPattern]);
     watcher.on('add', writeFile);
     watcher.on('change', writeFile);
     watcher.on('unlink', deleteFile);