diff --git a/README.md b/README.md
index c9659c4e..bcce7ddb 100644
--- a/README.md
+++ b/README.md
@@ -118,7 +118,7 @@ use Arkitect\Expression\ForClasses\ResideInOneOfTheseNamespaces;
 use Arkitect\Rules\Rule;
 
 return static function (Config $config): void {
-    $mvcClassSet = ClassSet::fromDir(__DIR__.'/mvc');
+    $mvcClassSet = ClassSet::fromDir(__DIR__.'/mvc', __DIR__.'/lib/my-lib/src');
 
     $rules = [];
 
diff --git a/src/ClassSet.php b/src/ClassSet.php
index 519a8953..3430b324 100644
--- a/src/ClassSet.php
+++ b/src/ClassSet.php
@@ -7,15 +7,15 @@
 
 class ClassSet implements \IteratorAggregate
 {
-    /** @var string */
-    private $directory;
+    /** @var string[] */
+    private $directoryList;
 
     /** @var array */
     private $exclude;
 
-    private function __construct(string $directory)
+    private function __construct(string ...$directoryList)
     {
-        $this->directory = $directory;
+        $this->directoryList = $directoryList;
         $this->exclude = [];
     }
 
@@ -26,21 +26,21 @@ public function excludePath(string $pattern): self
         return $this;
     }
 
-    public static function fromDir(string $directory): self
+    public static function fromDir(string ...$directoryList): self
     {
-        return new self($directory);
+        return new self(...$directoryList);
     }
 
     public function getDir(): string
     {
-        return $this->directory;
+        return implode(', ', $this->directoryList);
     }
 
     public function getIterator(): \Traversable
     {
         $finder = (new Finder())
             ->files()
-            ->in($this->directory)
+            ->in($this->directoryList)
             ->name('*.php')
             ->sortByName()
             ->followLinks()
diff --git a/tests/Unit/ClassSetTest.php b/tests/Unit/ClassSetTest.php
index 5ea3dca1..c9ba60c0 100644
--- a/tests/Unit/ClassSetTest.php
+++ b/tests/Unit/ClassSetTest.php
@@ -10,6 +10,30 @@
 
 class ClassSetTest extends TestCase
 {
+    public function test_can_exclude_files_or_directories_from_multiple_dir_class_set(): void
+    {
+        $path = $this->createMvcProjectStructure();
+
+        $set = ClassSet::fromDir($path.'/Controller', $path.'/Model')
+            ->excludePath('Repository');
+
+        $expected = [
+            $path.'/Controller/CatalogController.php',
+            $path.'/Controller/Foo.php',
+            $path.'/Controller/ProductsController.php',
+            $path.'/Controller/UserController.php',
+            $path.'/Controller/YieldController.php',
+            $path.'/Model/Catalog.php',
+            $path.'/Model/Products.php',
+            $path.'/Model/User.php',
+        ];
+        $actual = array_values(array_map(function ($item) {
+            /** @var \SplFileInfo $item */
+            return $item->getPathname();
+        }, iterator_to_array($set)));
+        self::assertEquals($expected, $actual);
+    }
+
     public function test_can_exclude_files_or_directories(): void
     {
         $path = $this->createMvcProjectStructure();