diff --git a/README.md b/README.md
index a6241cd..f00a60d 100644
--- a/README.md
+++ b/README.md
@@ -120,17 +120,23 @@ hook({
 });
 ```
 
-### `append` array
+### `devMode` boolean
 
-Appends custom plugins to the end of the PostCSS pipeline. Since the `require` function is synchronous, you should provide synchronous plugins only.
+Helps you to invalidate cache of all `require` calls. Usually used for the development purpose. Also overrides behavior, imposed by `NODE_ENV` environment variable. For example:
 
-### `prepend` array
+```javascript
+hook({
+  devMode: false,
+});
+```
 
-Prepends custom plugins to the beginning of the PostCSS pipeline. Since the `require` function is synchronous, you should provide synchronous plugins only.
+### `extensions` array
 
-### `use` array
+Attach the require hook to additional file extensions (for example `['.scss']`).
 
-Provides the full list of PostCSS plugins to the pipeline. Providing this cancels `append`, `prepend`, `createImportedName`, `generateScopedName` options. Synchronous plugins only.
+### `ignore` function|regex|string
+
+Provides possibility to exclude particular files from processing. Supports glob and regular expressions syntax. Also you may provide custom function.
 
 ### `preprocessCss` function
 
@@ -163,31 +169,31 @@ hook({
 });
 ```
 
-### `devMode` boolean
+### `processorOpts` object
 
-Helps you to invalidate cache of all `require` calls. Usually used for the development purpose. Also overrides behavior, imposed by `NODE_ENV` environment variable. For example:
+Provides possibility to pass custom options to the [LazyResult instance](https://github.com/postcss/postcss/blob/master/docs/api.md#processorprocesscss-opts). It can be usefull if you want to set the custom parser, for example: [postcss-less](https://github.com/gilt/postcss-less).
+
+```javascript
+const hook = require('css-modules-require-hook');
+const lessParser = require('postcss-less').parse;
 
-```bash
 hook({
-  devMode: false,
+  extensions: '.less',
+  processorOpts: {parser: lessParser},
 });
 ```
 
-### `extensions` array
-
-Attach the require hook to additional file extensions (for example `['.scss']`).
-
-### `ignore` function|regex|string
+### `append` array
 
-Provides possibility to exclude particular files from processing. Supports glob and regular expressions syntax. Also you may provide custom function.
+Appends custom plugins to the end of the PostCSS pipeline. Since the `require` function is synchronous, you should provide synchronous plugins only.
 
-### `rootDir` string
+### `prepend` array
 
-Provides absolute path to the project directory. Providing this will result in better generated class names. It can be obligatory, if you run require hook and build tools (like [css-modulesify](https://github.com/css-modules/css-modulesify)) from different working directories.
+Prepends custom plugins to the beginning of the PostCSS pipeline. Since the `require` function is synchronous, you should provide synchronous plugins only.
 
-### `to` string
+### `use` array
 
-Provides `to` option to the [LazyResult instance](https://github.com/postcss/postcss/blob/master/docs/api.md#processorprocesscss-opts).
+Provides the full list of PostCSS plugins to the pipeline. Providing this cancels `append`, `prepend`, `createImportedName`, `generateScopedName` options. Synchronous plugins only.
 
 ### `createImportedName` function
 
@@ -224,6 +230,11 @@ hook({
 
 Short alias for the [postcss-modules-local-by-default](https://github.com/css-modules/postcss-modules-local-by-default) plugin's option.
 
+### `rootDir` string
+
+Provides absolute path to the project directory. Providing this will result in better generated class names. It can be obligatory, if you run require hook and build tools (like [css-modulesify](https://github.com/css-modules/css-modulesify)) from different working directories.
+
+
 ## Debugging
 
 [debug](https://www.npmjs.com/package/debug) package is used for debugging. So to turn it on simply specify the **DEBUG** environment variable:
diff --git a/lib/index.js b/lib/index.js
index 70fccc3..abd894d 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -26,7 +26,7 @@ module.exports = function setupHook({
   ignore,
   preprocessCss = identity,
   processCss,
-  to,
+  processorOpts,
   append = [],
   prepend = [],
   createImportedName,
@@ -96,7 +96,7 @@ module.exports = function setupHook({
 
     const source = preprocessCss(readFileSync(filename, 'utf8'), filename);
     // https://github.com/postcss/postcss/blob/master/docs/api.md#processorprocesscss-opts
-    const lazyResult = runner.process(source, assign({}, {from: filename}));
+    const lazyResult = runner.process(source, assign({}, processorOpts, {from: filename}));
 
     // https://github.com/postcss/postcss/blob/master/docs/api.md#lazywarnings
     lazyResult.warnings().forEach(message => console.warn(message.text));
diff --git a/lib/validate.js b/lib/validate.js
index b12cd6f..9ddc925 100644
--- a/lib/validate.js
+++ b/lib/validate.js
@@ -9,7 +9,7 @@ const rules = {
   ignore:             'function|regex|string',
   preprocessCss:      'function',
   processCss:         'function',
-  to:                 'string',
+  processorOpts:      'object',
   // plugins
   append:             'array',
   prepend:            'array',
@@ -24,6 +24,7 @@ const tests = {
   array:    require('lodash').isArray,
   boolean:  require('lodash').isBoolean,
   function: require('lodash').isFunction,
+  object:   require('lodash').isPlainObject,
   regex:    require('lodash').isRegExp,
   string:   require('lodash').isString,
 };
diff --git a/package.json b/package.json
index 3bbe049..7177a41 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "css-modules-require-hook",
-  "version": "3.0.0",
+  "version": "4.0.0",
   "description": "A require hook to compile CSS Modules on the fly",
   "main": "lib/index.js",
   "engines": {
@@ -42,7 +42,7 @@
     "glob-to-regexp": "^0.1.0",
     "icss-replace-symbols": "^1.0.2",
     "lodash": "^4.3.0",
-    "postcss": "^5.0.15",
+    "postcss": "^5.0.19",
     "postcss-modules-extract-imports": "^1.0.0",
     "postcss-modules-local-by-default": "^1.0.1",
     "postcss-modules-parser": "^1.1.0",
@@ -57,6 +57,7 @@
     "in-publish": "^2.0.0",
     "isparta": "^4.0.0",
     "mocha": "^2.4.5",
+    "postcss-less": "^0.2.0",
     "sinon": "^1.17.3"
   }
 }
diff --git a/test/api/fixture/oceanic.less b/test/api/fixture/oceanic.less
new file mode 100644
index 0000000..7e4881c
--- /dev/null
+++ b/test/api/fixture/oceanic.less
@@ -0,0 +1,4 @@
+.color
+{
+  background: #1e2a35;
+}
diff --git a/test/api/processorOpts.js b/test/api/processorOpts.js
new file mode 100644
index 0000000..3d0a69e
--- /dev/null
+++ b/test/api/processorOpts.js
@@ -0,0 +1,25 @@
+const detachHook = require('../sugar').detachHook;
+const dropCache = require('../sugar').dropCache;
+const identity = require('lodash').identity;
+
+const lessParser = require('postcss-less').parse;
+
+// https://github.com/postcss/postcss/blob/master/docs/api.md#processorprocesscss-opts
+suite('api/processorOpts()', () => {
+  test('should provide possibility to specify custom processor options, for example: parser', () => {
+    const tokens = require('./fixture/oceanic.less');
+    assert.deepEqual(tokens, {color: '_test_api_fixture_oceanic__color'});
+  });
+
+  setup(() => {
+    hook({
+      extensions: '.less',
+      processorOpts: {parser: lessParser},
+    });
+  });
+
+  teardown(() => {
+    detachHook('.less');
+    dropCache('./api/fixture/oceanic.less');
+  });
+});