diff --git a/tests/Comment/CommentTest.php b/tests/Comment/CommentTest.php
index 14a0b240..29385f01 100644
--- a/tests/Comment/CommentTest.php
+++ b/tests/Comment/CommentTest.php
@@ -3,7 +3,9 @@
 namespace Sabberworm\CSS\Tests\Comment;
 
 use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Comment\Comment;
 use Sabberworm\CSS\OutputFormat;
+use Sabberworm\CSS\Renderable;
 use Sabberworm\CSS\Tests\ParserTest as TestsParserTest;
 
 /**
@@ -14,6 +16,97 @@
  */
 class CommentTest extends TestCase
 {
+    /**
+     * @test
+     */
+    public function implementsRenderable()
+    {
+        $subject = new Comment();
+
+        self::assertInstanceOf(Renderable::class, $subject);
+    }
+
+    /**
+     * @test
+     */
+    public function getCommentOnEmptyInstanceReturnsReturnsEmptyString()
+    {
+        $subject = new Comment();
+
+        self::assertSame('', $subject->getComment());
+    }
+
+    /**
+     * @test
+     */
+    public function getCommentInitiallyReturnsCommentPassedToConstructor()
+    {
+        $comment = 'There is no spoon.';
+        $subject = new Comment($comment);
+
+        self::assertSame($comment, $subject->getComment());
+    }
+
+    /**
+     * @test
+     */
+    public function setCommentSetsComments()
+    {
+        $comment = 'There is no spoon.';
+        $subject = new Comment();
+
+        $subject->setComment($comment);
+
+        self::assertSame($comment, $subject->getComment());
+    }
+
+    /**
+     * @test
+     */
+    public function getLineNoOnEmptyInstanceReturnsReturnsZero()
+    {
+        $subject = new Comment();
+
+        self::assertSame(0, $subject->getLineNo());
+    }
+
+    /**
+     * @test
+     */
+    public function getLineNoInitiallyReturnsLineNumberPassedToConstructor()
+    {
+        $lineNumber = 42;
+        $subject = new Comment('', $lineNumber);
+
+        self::assertSame($lineNumber, $subject->getLineNo());
+    }
+
+    /**
+     * @test
+     */
+    public function toStringRendersCommentEnclosedInCommentDelimiters()
+    {
+        $comment = 'There is no spoon.';
+        $subject = new Comment();
+
+        $subject->setComment($comment);
+
+        self::assertSame('/*' . $comment . '*/', (string)$subject);
+    }
+
+    /**
+     * @test
+     */
+    public function renderRendersCommentEnclosedInCommentDelimiters()
+    {
+        $comment = 'There is no spoon.';
+        $subject = new Comment();
+
+        $subject->setComment($comment);
+
+        self::assertSame('/*' . $comment . '*/', $subject->render(new OutputFormat()));
+    }
+
     /**
      * @test
      */