diff --git a/README.md b/README.md
index 5e166d9..6900f35 100644
--- a/README.md
+++ b/README.md
@@ -89,7 +89,7 @@ Compared to the previous approach, this method decouples the React Fast Refresh
 ### test
 
 - Type: [Rspack.RuleSetCondition](https://rspack.rs/config/module-rules#condition)
-- Default: `undefined`
+- Default: `/\.(?:js|jsx|mjs|cjs|ts|tsx|mts|cts)$/`
 
 Specifies which files should be processed by the React Refresh loader. This option is passed to the `builtin:react-refresh-loader` as the `rule.test` condition.
 
@@ -104,7 +104,7 @@ new ReactRefreshPlugin({
 ### include
 
 - Type: [Rspack.RuleSetCondition](https://rspack.rs/config/module-rules#condition)
-- Default: `/\.(?:js|jsx|mjs|cjs|ts|tsx|mts|cts)$/`
+- Default: `undefined`
 
 Explicitly includes files to be processed by the React Refresh loader. This option is passed to the `builtin:react-refresh-loader` as the `rule.include` condition.
 
diff --git a/src/options.ts b/src/options.ts
index 770c59b..6203c5f 100644
--- a/src/options.ts
+++ b/src/options.ts
@@ -5,6 +5,7 @@ export type PluginOptions = {
    * Specifies which files should be processed by the React Refresh loader.
    * This option is passed to the `builtin:react-refresh-loader` as the `rule.test` condition.
    * Works identically to Rspack's `rule.test` option.
+   * @default /\.(?:js|jsx|mjs|cjs|ts|tsx|mts|cts)$/
    * @see https://rspack.rs/config/module-rules#rulestest
    */
   test?: RuleSetCondition;
@@ -13,7 +14,7 @@ export type PluginOptions = {
    * This option is passed to the `builtin:react-refresh-loader` as the `rule.include` condition.
    * Use this to limit processing to specific directories or file patterns.
    * Works identically to Rspack's `rule.include` option.
-   * @default /\.(?:js|jsx|mjs|cjs|ts|tsx|mts|cts)$/
+   * @default undefined
    * @see https://rspack.rs/config/module-rules#rulesinclude
    */
   include?: RuleSetCondition | null;
@@ -93,8 +94,8 @@ const d = <K extends keyof PluginOptions>(
 export function normalizeOptions(
   options: PluginOptions,
 ): NormalizedPluginOptions {
+  d(options, 'test', /\.(?:js|jsx|mjs|cjs|ts|tsx|mts|cts)$/);
   d(options, 'exclude', /node_modules/i);
-  d(options, 'include', /\.(?:js|jsx|mjs|cjs|ts|tsx|mts|cts)$/);
   d(options, 'library');
   d(options, 'forceEnable', false);
   d(options, 'injectLoader', true);
diff --git a/test/fixtures/include/index.js b/test/fixtures/include/index.js
new file mode 100644
index 0000000..325598e
--- /dev/null
+++ b/test/fixtures/include/index.js
@@ -0,0 +1,3 @@
+import './style.css';
+
+export default 'include';
diff --git a/test/fixtures/include/style.css b/test/fixtures/include/style.css
new file mode 100644
index 0000000..8579bef
--- /dev/null
+++ b/test/fixtures/include/style.css
@@ -0,0 +1,3 @@
+.include {
+  color: red;
+}
diff --git a/test/test.spec.ts b/test/test.spec.ts
index 8518255..8c66906 100644
--- a/test/test.spec.ts
+++ b/test/test.spec.ts
@@ -12,6 +12,7 @@ type Outputs = {
   fixture: string;
   runtime: string;
   vendor: string;
+  css?: string;
 };
 
 type CompilationResult = {
@@ -22,6 +23,10 @@ type CompilationResult = {
 };
 
 const uniqueName = 'ReactRefreshLibrary';
+const readOutput = (fixturePath: string, file: string) =>
+  fs.existsSync(path.join(fixturePath, 'dist', file))
+    ? fs.readFileSync(path.join(fixturePath, 'dist', file), 'utf-8')
+    : '';
 
 const compileWithReactRefresh = (
   fixturePath: string,
@@ -32,7 +37,9 @@ const compileWithReactRefresh = (
     const cjsEntry = path.join(fixturePath, 'index.js');
     const ctsEntry = path.join(fixturePath, 'index.cjs');
     const mjsEntry = path.join(fixturePath, 'index.mjs');
-    const customLoader = path.join(fixturePath, 'loader.cjs');
+    const customLoader = fs.existsSync(path.join(fixturePath, 'loader.cjs'))
+      ? path.join(fixturePath, 'loader.cjs')
+      : path.join(import.meta.dirname, 'fixtures/loader/loader.cjs');
     const entry = fs.existsSync(cjsEntry)
       ? cjsEntry
       : fs.existsSync(ctsEntry)
@@ -52,6 +59,14 @@ const compileWithReactRefresh = (
           uniqueName,
           assetModuleFilename: '[name][ext]',
         },
+        module: {
+          rules: [
+            {
+              test: /\.css$/,
+              type: 'css/auto',
+            },
+          ],
+        },
         resolveLoader: {
           alias: {
             'custom-react-refresh-loader': customLoader,
@@ -112,22 +127,11 @@ const compileWithReactRefresh = (
           error,
           stats,
           outputs: {
-            reactRefresh: fs.readFileSync(
-              path.join(fixturePath, 'dist', 'react-refresh.js'),
-              'utf-8',
-            ),
-            fixture: fs.readFileSync(
-              path.join(fixturePath, 'dist', 'fixture.js'),
-              'utf-8',
-            ),
-            runtime: fs.readFileSync(
-              path.join(fixturePath, 'dist', 'runtime.js'),
-              'utf-8',
-            ),
-            vendor: fs.readFileSync(
-              path.join(fixturePath, 'dist', 'vendor.js'),
-              'utf-8',
-            ),
+            reactRefresh: readOutput(fixturePath, 'react-refresh.js'),
+            fixture: readOutput(fixturePath, 'fixture.js'),
+            runtime: readOutput(fixturePath, 'runtime.js'),
+            vendor: readOutput(fixturePath, 'vendor.js'),
+            css: readOutput(fixturePath, 'fixture.css') || undefined,
           },
           plugin,
         });
@@ -301,4 +305,19 @@ describe('react-refresh-rspack-plugin', () => {
     expect(fixture).toContain('TEST_LOADER');
     expect(fixture).not.toContain('function $RefreshReg$');
   });
+
+  it('should keep the default extension filter when include targets a directory', async () => {
+    const {
+      outputs: { fixture, css },
+    } = await compileWithReactRefresh(
+      path.join(import.meta.dirname, 'fixtures/include'),
+      {
+        include: path.join(import.meta.dirname, 'fixtures/include'),
+        reactRefreshLoader: 'custom-react-refresh-loader',
+      },
+    );
+    expect(fixture).toContain('TEST_LOADER');
+    expect(css).toBeDefined();
+    expect(css).not.toContain('TEST_LOADER');
+  });
 });