diff --git a/src/Schemator.php b/src/Schemator.php
index 8e151be..fb9d80b 100644
--- a/src/Schemator.php
+++ b/src/Schemator.php
@@ -36,15 +36,18 @@ public function __construct(string $pathDelimiter = '.')
      * Converts input data with using schema
      * @param array $source input data to convert
      * @param array $schema schema for converting
-     * @return array converted data
+     * @return array|mixed converted data
      * @throws SchematorException
      */
-    public function exec(array $source, array $schema): array
+    public function exec(array $source, array $schema)
     {
         $result = [];
 
         foreach($schema as $key => $schemaItem) {
             $this->saveByPath($result, $key, $this->getValue($source, $schemaItem));
+            if($key === '') {
+                break;
+            }
         }
 
         return $result;
@@ -186,6 +189,11 @@ protected function runFilter(array $filterConfig, $source, array $rootSource)
      */
     protected function saveByPath(array &$source, string $path, $value): self
     {
+        if($path === '') {
+            $source = $value;
+            return $this;
+        }
+
         $arPath = explode($this->pathDelimiter, $path);
         $temp = &$source;
         foreach($arPath as $key) {
diff --git a/tests/unit/MassSchematorTest.php b/tests/unit/MassSchematorTest.php
index 5053904..d38d448 100644
--- a/tests/unit/MassSchematorTest.php
+++ b/tests/unit/MassSchematorTest.php
@@ -81,7 +81,7 @@ public function testNested()
             $result[] = $item;
         }
 
-        $exprectedResult = [
+        $expectedResult = [
             [
                 'my_city_id' => 100,
                 'my_country' => [
@@ -98,7 +98,19 @@ public function testNested()
             ],
         ];
 
-        $this->assertEquals($exprectedResult, $result);
+        $this->assertEquals($expectedResult, $result);
+    }
+
+    public function testExtra()
+    {
+        $massSchemator = new MassSchemator(new Schemator());
+        $cities = $this->getCities();
+
+        $result = $massSchemator->exec($cities, [
+            '' => 'name',
+        ]);
+
+        $this->assertEquals(['Novgorod', 'Moscow'], $result);
     }
 
     /**