diff --git a/src/CodeIQ/Greeter/Tests/GreeterTest.php b/src/CodeIQ/Greeter/Tests/GreeterTest.php
index 0bdfe0d..9098db2 100644
--- a/src/CodeIQ/Greeter/Tests/GreeterTest.php
+++ b/src/CodeIQ/Greeter/Tests/GreeterTest.php
@@ -19,11 +19,27 @@ class GreeterTest extends \PHPUnit_Framework_TestCase
     /**
      * @test
      */
-    public function あいさつする()
+    public function 朝ならおはようございます()
     {
+        $this->clock->expects($this->once())
+            ->method('getCurrentTime')
+            ->will($this->returnValue(new \DateTimeImmutable('08:00:00')));
+
         $this->assertThat($this->SUT->greet(), $this->equalTo('おはようございます'));
     }
 
+    /**
+     * @test
+     */
+    public function 朝でないならあいさつなし()
+    {
+        $this->clock->expects($this->once())
+            ->method('getCurrentTime')
+            ->will($this->returnValue(new \DateTimeImmutable('15:00:00')));
+
+        $this->assertThat($this->SUT->greet(), $this->equalTo(''));
+    }
+
     protected function setUp()
     {
         $this->clock = $this->getMock('CodeIQ\Greeter\Clock');