diff --git a/test/__snapshots__/built-in-css.test.js.snap b/test/__snapshots__/built-in-css.test.js.snap
index c49db5e..6e0230b 100644
--- a/test/__snapshots__/built-in-css.test.js.snap
+++ b/test/__snapshots__/built-in-css.test.js.snap
@@ -16,6 +16,16 @@ exports[`built-in CSS support > should emit assets from \`url()\` 2`] = `
 []
 `;
 
+exports[`built-in CSS support > should emit less warning as webpack warning 1`] = `
+[
+  "ModuleWarning: Module Warning (from \`replaced original path\`):\\nWARNING: extend ' .body1' has no matches"
+]
+`;
+
+exports[`built-in CSS support > should emit less warning as webpack warning 2`] = `
+[]
+`;
+
 exports[`built-in CSS support > should generate source maps 1`] = `
 []
 `;
@@ -24,6 +34,30 @@ exports[`built-in CSS support > should generate source maps 2`] = `
 []
 `;
 
+exports[`built-in CSS support > should not treat a file as a CSS module with the \`css\` type 1`] = `
+".box {\\n  color: #fe33ac;\\n}\\n.nested {\\n  color: #fe33ac;\\n  padding: 10px;\\n}\\n\\n"
+`;
+
+exports[`built-in CSS support > should not treat a file as a CSS module with the \`css\` type 2`] = `
+[]
+`;
+
+exports[`built-in CSS support > should not treat a file as a CSS module with the \`css\` type 3`] = `
+[]
+`;
+
+exports[`built-in CSS support > should treat any file as a CSS module with the \`css/module\` type 1`] = `
+".built-in-css_basic_less-imported {\\n  color: hotpink;\\n}\\n.built-in-css_basic_less-modules-dir-some-module {\\n  color: hotpink;\\n}\\n.built-in-css_basic_less-box {\\n  color: #fe33ac;\\n  border-color: #fdcdea;\\n  background: url(circle.svg);\\n}\\n\\n"
+`;
+
+exports[`built-in CSS support > should treat any file as a CSS module with the \`css/module\` type 2`] = `
+[]
+`;
+
+exports[`built-in CSS support > should treat any file as a CSS module with the \`css/module\` type 3`] = `
+[]
+`;
+
 exports[`built-in CSS support > should work 1`] = `
 ".imported {\\n  color: hotpink;\\n}\\n.modules-dir-some-module {\\n  color: hotpink;\\n}\\n.box {\\n  color: #fe33ac;\\n  border-color: #fdcdea;\\n  background: url(circle.svg);\\n}\\n\\n"
 `;
diff --git a/test/built-in-css.test.js b/test/built-in-css.test.js
index 66a5413..344a274 100644
--- a/test/built-in-css.test.js
+++ b/test/built-in-css.test.js
@@ -55,6 +55,35 @@ describe("built-in CSS support", { timeout: 30000 }, () => {
     t.assert.snapshot(getErrors(stats));
   });
 
+  it("should not treat a file as a CSS module with the `css` type", async (t) => {
+    const testId = "./built-in-css/style.module.less";
+    const compiler = getCssCompiler(testId, {}, { type: "css" });
+    const stats = await compile(compiler);
+    const css = readAsset("main.css", compiler, stats);
+
+    assert.match(css, /^\.box\b/m, "Expected local class names to be kept");
+    t.assert.snapshot(css);
+    t.assert.snapshot(getWarnings(stats));
+    t.assert.snapshot(getErrors(stats));
+  });
+
+  it("should treat any file as a CSS module with the `css/module` type", async (t) => {
+    const testId = "./built-in-css/basic.less";
+    const compiler = getCssCompiler(testId, {}, { type: "css/module" });
+    const stats = await compile(compiler);
+    const css = readAsset("main.css", compiler, stats);
+
+    assert.doesNotMatch(
+      css,
+      /^\.box\b/m,
+      "Expected local class names to be renamed",
+    );
+    assert.match(css, /^\.[\w-]+-box\b/m);
+    t.assert.snapshot(css);
+    t.assert.snapshot(getWarnings(stats));
+    t.assert.snapshot(getErrors(stats));
+  });
+
   it("should work with the `lessOptions` option", async (t) => {
     const testId = "./built-in-css/variables.less";
     const compiler = getCssCompiler(testId, {
@@ -104,6 +133,15 @@ describe("built-in CSS support", { timeout: 30000 }, () => {
     t.assert.snapshot(getErrors(stats));
   });
 
+  it("should emit less warning as webpack warning", async (t) => {
+    const testId = "./warn.less";
+    const compiler = getCssCompiler(testId);
+    const stats = await compile(compiler);
+
+    t.assert.snapshot(getWarnings(stats));
+    t.assert.snapshot(getErrors(stats));
+  });
+
   it("should emit an error on a broken file", async (t) => {
     const testId = "./error.less";
     const compiler = getCssCompiler(testId);
diff --git a/test/helpers/getCssCompiler.js b/test/helpers/getCssCompiler.js
index f20d2e9..ccffc30 100644
--- a/test/helpers/getCssCompiler.js
+++ b/test/helpers/getCssCompiler.js
@@ -11,10 +11,11 @@ const __dirname = path.dirname(fileURLToPath(import.meta.url));
  * (i.e. `experiments.css`) instead of `css-loader`/`style-loader`.
  * @param {string} fixture fixture
  * @param {object} loaderOptions loader options
- * @param {object} config webpack config
+ * @param {object} config webpack config, the `type` property is used as the module type of the rule
  * @returns {Compiler} compiler
  */
 export default (fixture, loaderOptions = {}, config = {}) => {
+  const { type = "css/auto", ...webpackConfig } = config;
   const fullConfig = {
     mode: "development",
     devtool: config.devtool || false,
@@ -36,7 +37,7 @@ export default (fixture, loaderOptions = {}, config = {}) => {
       rules: [
         {
           test: /\.less$/i,
-          type: "css/auto",
+          type,
           use: [
             {
               loader: path.resolve(__dirname, "../../src/index.js"),
@@ -47,7 +48,7 @@ export default (fixture, loaderOptions = {}, config = {}) => {
       ],
     },
     plugins: [],
-    ...config,
+    ...webpackConfig,
   };
 
   const compiler = webpack(fullConfig);