diff --git a/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php b/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php
index b84b35950c8..9c7fcf66aa3 100644
--- a/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php
+++ b/lib/Cake/Test/Case/Network/Email/CakeEmailTest.php
@@ -275,6 +275,10 @@ public function testTo() {
 		$expected = array('cake@cakephp.org' => 'CakePHP');
 		$this->assertSame($expected, $this->CakeEmail->to());
 
+		$this->CakeEmail->to('cake@cake_php.org', 'CakePHPUnderscore');
+		$expected = array('cake@cake_php.org', 'CakePHPUnderscore');
+		$this->assertSame($expected, $this->CakeEmail->to());
+
 		$list = array(
 			'root@localhost' => 'root',
 			'bjørn@hammeröath.com' => 'Bjorn',