diff --git a/core/lib/Drupal/Core/Render/RenderVariable.php b/core/lib/Drupal/Core/Render/RenderVariable.php
index 0253166..83e4497 100644
--- a/core/lib/Drupal/Core/Render/RenderVariable.php
+++ b/core/lib/Drupal/Core/Render/RenderVariable.php
@@ -83,6 +83,7 @@ public static function wrap($thing, $prefix, $suffix) {
     $output = static::makeRenderArray($thing);
     $output['#prefix'] = $prefix;
     $output['#suffix'] = $suffix;
+    return $output;
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Core/Render/RenderVariableTest.php b/core/tests/Drupal/Tests/Core/Render/RenderVariableTest.php
index f58ffa6..fd007c3 100644
--- a/core/tests/Drupal/Tests/Core/Render/RenderVariableTest.php
+++ b/core/tests/Drupal/Tests/Core/Render/RenderVariableTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\Tests\Core\Render;
 
 use Drupal\Core\Render\RenderVariable;
+use Drupal\Core\Render\SafeString;
 
 /**
  * @coversDefaultClass \Drupal\Core\Render\RenderVariable
@@ -37,11 +38,13 @@ public function providerRenderVariablePrefix() {
     $data[] = ['1 2 &lt;em&gt;blah&lt;/em&gt;', '<em>blah</em>', ['1', ' ', '2', ' ']];
     $data[] = ['test<em>blah</em>', ['#markup' => '<em>blah</em>'], ['test']];
     $data[] = ['test <em>blah</em>', ['#markup' => '<em>blah</em>'], ['test', ' ']];
+    $data[] = ['test<em>blah</em>', SafeString::create('<em>blah</em>'), ['test']];
+    $data[] = ['test <em>blah</em>', SafeString::create('<em>blah</em>'), ['test', ' ']];
     return $data;
   }
 
   /**
-   * @covers ::prefix
+   * @covers ::suffix
    *
    * @dataProvider providerRenderVariableSuffix
    */
@@ -62,6 +65,30 @@ public function providerRenderVariableSuffix() {
     $data[] = ['&lt;em&gt;blah&lt;/em&gt;1 2', '<em>blah</em>', ['1', ' ', '2']];
     $data[] = ['<em>blah</em>test', ['#markup' => '<em>blah</em>'], ['test']];
     $data[] = ['<em>blah</em> test', ['#markup' => '<em>blah</em>'], [' ', 'test']];
+    $data[] = ['<em>blah</em>test', SafeString::create('<em>blah</em>'), ['test']];
+    $data[] = ['<em>blah</em> test', SafeString::create('<em>blah</em>'), [' ', 'test']];
+    return $data;
+  }
+
+  /**
+   * @covers ::wrap
+   *
+   * @dataProvider providerRenderVariableWrap
+   */
+  public function testRenderVariableWrap($expected, $variable, $prefix, $suffix) {
+    $build = RenderVariable::wrap($variable, $prefix, $suffix);
+    $render_output = $this->renderer->renderRoot($build);
+    $this->assertEquals($expected, (string) $render_output);
+  }
+
+  /**
+   * @return array
+   */
+  public function providerRenderVariableWrap() {
+    $data = [];
+    $data[] = ['<span>&lt;em&gt;blah&lt;/em&gt;</span>', '<em>blah</em>', '<span>', '</span>'];
+    $data[] = ['<span><em>blah</em></span>', ['#markup' => '<em>blah</em>'], '<span>', '</span>'];
+    $data[] = ['<span><em>bar</em></span>', SafeString::create('<em>bar</em>'), '<span>', '</span>'];
     return $data;
   }