diff --git a/tests/unit/Block/Renderer/HtmlBlockRendererTest.php b/tests/unit/Block/Renderer/HtmlBlockRendererTest.php
index 54a13d1e5e..6cbfc95297 100644
--- a/tests/unit/Block/Renderer/HtmlBlockRendererTest.php
+++ b/tests/unit/Block/Renderer/HtmlBlockRendererTest.php
@@ -50,6 +50,28 @@ public function testRender()
         $this->assertContains('<button>Test</button>', $result);
     }
 
+    public function testRenderSafeMode()
+    {
+        $this->renderer->setConfiguration(new Configuration([
+            'safe' => true,
+        ]));
+
+        /** @var HtmlBlock|\PHPUnit_Framework_MockObject_MockObject $block */
+        $block = $this->getMockBuilder('League\CommonMark\Block\Element\HtmlBlock')
+            ->setConstructorArgs([HtmlBlock::TYPE_6_BLOCK_ELEMENT])
+            ->getMock();
+        $block->expects($this->any())
+            ->method('getStringContent')
+            ->will($this->returnValue('<button>Test</button>'));
+
+        $fakeRenderer = new FakeHtmlRenderer();
+
+        $result = $this->renderer->render($block, $fakeRenderer);
+
+        $this->assertInternalType('string', $result);
+        $this->assertEquals('', $result);
+    }
+
     /**
      * @expectedException \InvalidArgumentException
      */
diff --git a/tests/unit/Inline/Renderer/HtmlInlineRendererTest.php b/tests/unit/Inline/Renderer/HtmlInlineRendererTest.php
index e188eb16da..6a6e42c44e 100644
--- a/tests/unit/Inline/Renderer/HtmlInlineRendererTest.php
+++ b/tests/unit/Inline/Renderer/HtmlInlineRendererTest.php
@@ -43,6 +43,21 @@ public function testRender()
         $this->assertContains('<h1>Test</h1>', $result);
     }
 
+    public function testRenderSafeMode()
+    {
+        $this->renderer->setConfiguration(new Configuration([
+            'safe' => true,
+        ]));
+
+        $inline = new HtmlInline('<h1>Test</h1>');
+        $fakeRenderer = new FakeHtmlRenderer();
+
+        $result = $this->renderer->render($inline, $fakeRenderer);
+
+        $this->assertInternalType('string', $result);
+        $this->assertEquals('', $result);
+    }
+
     /**
      * @expectedException \InvalidArgumentException
      */