diff --git a/src/Hydrator/ClassMethods.php b/src/Hydrator/ClassMethods.php
index 012e01150..4218eef3c 100644
--- a/src/Hydrator/ClassMethods.php
+++ b/src/Hydrator/ClassMethods.php
@@ -33,18 +33,18 @@
 class ClassMethods implements HydratorInterface
 {
     /**
-     * CamelCase usage to extract attribute with getter/setter method name
+     * Flag defining whether array keys are underscore-separated (true) or camel case (false)
      * @var boolean
      */
-    protected $useCamelCase;
+    protected $underscoreSeparatedKeys;
     
     /**
      * Define if extract values will use camel case or name with underscore
-     * @param boolean $useCamelCase 
+     * @param boolean $underscoreSeparatedKeys 
      */
-    public function __construct($useCamelCase = true)
+    public function __construct($underscoreSeparatedKeys = true)
     {
-        $this->useCamelCase = $useCamelCase;
+        $this->underscoreSeparatedKeys = $underscoreSeparatedKeys;
     }
     
     /**
@@ -81,7 +81,7 @@ public function extract($object)
                 }
                 $attribute = substr($method, 3);
                 $attribute = lcfirst($attribute);
-                if (!$this->useCamelCase) {
+                if ($this->underscoreSeparatedKeys) {
                     $attribute = preg_replace_callback('/([A-Z])/', $transform, $attribute);
                 }
 
@@ -131,7 +131,7 @@ public function hydrate(array $data, $object)
         };
 
         foreach ($data as $property => $value) {
-            if (!$this->useCamelCase) {
+            if ($this->underscoreSeparatedKeys) {
                 $property = preg_replace_callback('/(_[a-z])/', $transform, $property);
             }
             $method = 'set' . ucfirst($property);
diff --git a/test/HydratorTest.php b/test/HydratorTest.php
index d6fd41d23..85efb43c8 100644
--- a/test/HydratorTest.php
+++ b/test/HydratorTest.php
@@ -95,7 +95,7 @@ public function testHydratorReflection()
 
     public function testHydratorClassMethodsCamelCase()
     {
-        $hydrator = new ClassMethods(true);
+        $hydrator = new ClassMethods(false);
         $datas = $hydrator->extract($this->classMethodsCamelCase);
         $this->assertTrue(isset($datas['fooBar']));
         $this->assertEquals($datas['fooBar'], '1');
@@ -109,7 +109,7 @@ public function testHydratorClassMethodsCamelCase()
     
     public function testHydratorClassMethodsCamelCaseWithSetterMissing()
     {
-        $hydrator = new ClassMethods(true);
+        $hydrator = new ClassMethods(false);
         $datas = $hydrator->extract($this->classMethodsCamelCaseMissing);
         $this->assertTrue(isset($datas['fooBar']));
         $this->assertEquals($datas['fooBar'], '1');
@@ -123,7 +123,7 @@ public function testHydratorClassMethodsCamelCaseWithSetterMissing()
     
     public function testHydratorClassMethodsUnderscore()
     {
-        $hydrator = new ClassMethods(false);
+        $hydrator = new ClassMethods(true);
         $datas = $hydrator->extract($this->classMethodsUnderscore);
         $this->assertTrue(isset($datas['foo_bar']));
         $this->assertEquals($datas['foo_bar'], '1');
@@ -137,7 +137,7 @@ public function testHydratorClassMethodsUnderscore()
 
     public function testHydratorClassMethodsIgnoresInvalidValues()
     {
-        $hydrator = new ClassMethods(false);
+        $hydrator = new ClassMethods(true);
         $data = array(
             'foo_bar' => '1',
             'foo_bar_baz' => '2',
@@ -146,4 +146,18 @@ public function testHydratorClassMethodsIgnoresInvalidValues()
         $test = $hydrator->hydrate($data, $this->classMethodsUnderscore);
         $this->assertSame($this->classMethodsUnderscore, $test);
     }
+
+    public function testHydratorClassMethodsDefaultBehaviorIsConvertUnderscoreToCamelCase()
+    {
+        $hydrator = new ClassMethods();
+        $datas = $hydrator->extract($this->classMethodsUnderscore);
+        $this->assertTrue(isset($datas['foo_bar']));
+        $this->assertEquals($datas['foo_bar'], '1');
+        $this->assertTrue(isset($datas['foo_bar_baz']));
+        $this->assertFalse(isset($datas['fooBar']));
+        $test = $hydrator->hydrate(array('foo_bar' => 'foo', 'foo_bar_baz' => 'bar'), $this->classMethodsUnderscore);
+        $this->assertSame($this->classMethodsUnderscore, $test);
+        $this->assertEquals($test->getFooBar(), 'foo');
+        $this->assertEquals($test->getFooBarBaz(), 'bar');
+    }
 }