diff --git a/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php b/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php
index e9527280c..48ee47569 100644
--- a/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php
+++ b/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php
@@ -95,6 +95,20 @@ class EmailConfig {
 		'helpers' => array('Html', 'Form'),
 	);
 
+/**
+ * test config 2
+ *
+ * @var string
+ */
+	public $test2 = array(
+		'from' => array('some@example.com' => 'My website'),
+		'to' => array('test@example.com' => 'Testname'),
+		'subject' => 'Test mail subject',
+		'transport' => 'Smtp',
+		'host' => 'cakephp.org',
+		'timeout' => 60
+	);
+
 }
 
 /*
@@ -726,12 +740,13 @@ class CakeEmailTest extends CakeTestCase {
 		$this->assertSame($this->CakeEmail->config(), $config);
 
 		$this->CakeEmail->config(array());
-		$this->assertSame($transportClass->config(), array());
+		$this->assertSame($transportClass->config(), $config);
 
 		$config = array('test' => 'test@example.com');
 		$this->CakeEmail->config($config);
 		$expected = array('test' => 'test@example.com', 'test2' => true);
 		$this->assertSame($expected, $this->CakeEmail->config());
+		$this->assertSame($expected, $transportClass->config());
 	}
 
 /**
@@ -765,6 +780,35 @@ class CakeEmailTest extends CakeTestCase {
 		$this->assertEquals($configs->test['helpers'], $result);
 	}
 
+/**
+ * Test updating config doesn't reset transport's config.
+ *
+ * @return void
+ */
+	public function testConfigMerge() {
+		$this->CakeEmail->config('test2');
+
+		$expected = array(
+			'host' => 'cakephp.org',
+			'port' => 25,
+			'timeout' => 60,
+			'username' => null,
+			'password' => null,
+			'client' => null,
+			'tls' => false
+		);
+		$this->assertEquals($expected, $this->CakeEmail->transportClass()->config());
+
+		$this->CakeEmail->config(array('log' => true));
+		$result = $this->CakeEmail->transportClass()->config();
+		$expected += array('log' => true);
+		$this->assertEquals($expected, $this->CakeEmail->transportClass()->config());
+
+		$this->CakeEmail->config(array('timeout' => 45));
+		$result = $this->CakeEmail->transportClass()->config();
+		$this->assertEquals(45, $result['timeout']);
+	}
+
 /**
  * testSendWithContent method
  *