diff --git a/src/Validator/SchemaValidator.php b/src/Validator/SchemaValidator.php
index da4d213..9f1d2b8 100644
--- a/src/Validator/SchemaValidator.php
+++ b/src/Validator/SchemaValidator.php
@@ -81,10 +81,16 @@ private function validateByAttributes(array $object, $schemaId, $attributes, arr
                 if (!$attribute->isMultiValued()) {
                     $validationResult->add($propertyName, $parentPath, $schemaId, 'Attribute is not defined in schema as multi-valued, but got array');
                     continue;
-                } else {
-                    foreach ($value as $item) {
-                        $this->validateByAttributes($item, $schemaId, $attribute->getSubAttributes(), [], $validationResult, $propertyName);
+                }
+                foreach ($value as $item) {
+                    if (!is_array($item)) {
+                        if (!$attribute->isValueValid($item)) {
+                            $validationResult->add($propertyName, $parentPath, $schemaId, sprintf('Attribute has invalid value for type "%s"', $attribute->getType()));
+                        }
+                        continue;
                     }
+
+                    $this->validateByAttributes($item, $schemaId, $attribute->getSubAttributes(), [], $validationResult, $propertyName);
                 }
             } elseif ($this->isObject($value)) {
                 if ($attribute->isMultiValued()) {
diff --git a/tests/Validator/SchemaValidatorTest.php b/tests/Validator/SchemaValidatorTest.php
index edb6198..a771db7 100644
--- a/tests/Validator/SchemaValidatorTest.php
+++ b/tests/Validator/SchemaValidatorTest.php
@@ -44,6 +44,15 @@ public function test_full_user_representation()
         $this->assertEquals([], $result->getErrorsAsStrings());
     }
 
+    public function test_list()
+    {
+        $schema = new Schema('customUser');
+        $schema->addAttribute(AttributeBuilder::create('tags', ScimConstants::ATTRIBUTE_TYPE_STRING)
+            ->setMultiValued(true)->getAttribute(),
+        );
+        $this->assertEmpty($this->validator->validate(['tags' => ['foo']], $schema)->getErrors());
+    }
+
     public function test_enterprise_user_full()
     {
         $result = $this->validator->validate(