diff --git a/core/modules/views/src/Plugin/views/style/StylePluginBase.php b/core/modules/views/src/Plugin/views/style/StylePluginBase.php
index de927ccccdb..7274abdc04e 100644
--- a/core/modules/views/src/Plugin/views/style/StylePluginBase.php
+++ b/core/modules/views/src/Plugin/views/style/StylePluginBase.php
@@ -583,7 +583,7 @@ abstract class StylePluginBase extends PluginBase {
               $group_content = $this->view->field[$field]->options['label'] . ': ' . $group_content;
             }
             if ($rendered) {
-              $grouping = $group_content;
+              $grouping = (string) $group_content;
               if ($rendered_strip) {
                 $group_content = $grouping = strip_tags(htmlspecialchars_decode($group_content));
               }
diff --git a/core/modules/views/src/Tests/Plugin/StyleTest.php b/core/modules/views/src/Tests/Plugin/StyleTest.php
index 112988c062c..68ce82eb103 100644
--- a/core/modules/views/src/Tests/Plugin/StyleTest.php
+++ b/core/modules/views/src/Tests/Plugin/StyleTest.php
@@ -118,7 +118,7 @@ class StyleTest extends ViewTestBase {
     ));
 
     // Add the job and age field.
-    $view->displayHandlers->get('default')->overrideOption('fields', array(
+    $fields = array(
       'name' => array(
         'id' => 'name',
         'table' => 'views_test_data',
@@ -140,7 +140,8 @@ class StyleTest extends ViewTestBase {
         'relationship' => 'none',
         'label' => 'Age',
       ),
-    ));
+    );
+    $view->displayHandlers->get('default')->overrideOption('fields', $fields);
 
     // Now run the query and groupby the result.
     $this->executeView($view);
@@ -177,16 +178,16 @@ class StyleTest extends ViewTestBase {
     if ($stripped) {
 
       // Add some html to the result and expected value.
-      $rand = '<a data="' . $this->randomMachineName() . '" />';
-      $view->result[0]->views_test_data_job .= $rand;
-      $expected['Job: Singer']['rows']['Age: 25']['rows'][0]->views_test_data_job = 'Singer' . $rand;
+      $rand1 = '<a data="' . $this->randomMachineName() . '" />';
+      $view->result[0]->views_test_data_job .= $rand1;
+      $expected['Job: Singer']['rows']['Age: 25']['rows'][0]->views_test_data_job = 'Singer' . $rand1;
       $expected['Job: Singer']['group'] = 'Job: Singer';
-      $rand = '<a data="' . $this->randomMachineName() . '" />';
-      $view->result[1]->views_test_data_job .= $rand;
-      $expected['Job: Singer']['rows']['Age: 27']['rows'][1]->views_test_data_job = 'Singer' . $rand;
-      $rand = '<a data="' . $this->randomMachineName() . '" />';
-      $view->result[2]->views_test_data_job .= $rand;
-      $expected['Job: Drummer']['rows']['Age: 28']['rows'][2]->views_test_data_job = 'Drummer' . $rand;
+      $rand2 = '<a data="' . $this->randomMachineName() . '" />';
+      $view->result[1]->views_test_data_job .= $rand2;
+      $expected['Job: Singer']['rows']['Age: 27']['rows'][1]->views_test_data_job = 'Singer' . $rand2;
+      $rand3 = '<a data="' . $this->randomMachineName() . '" />';
+      $view->result[2]->views_test_data_job .= $rand3;
+      $expected['Job: Drummer']['rows']['Age: 28']['rows'][2]->views_test_data_job = 'Drummer' . $rand3;
       $expected['Job: Drummer']['group'] = 'Job: Drummer';
 
       $view->style_plugin->options['grouping'][0] = array('field' => 'job', 'rendered' => TRUE, 'rendered_strip' => TRUE);
@@ -204,19 +205,52 @@ class StyleTest extends ViewTestBase {
       $sets_new_value = $view->style_plugin->renderGrouping($view->result, $view->style_plugin->options['grouping'], FALSE);
 
       // Reorder the group structure to grouping by value.
-      $expected['Singer'] = $expected['Job: Singer'];
-      $expected['Singer']['rows']['25'] = $expected['Job: Singer']['rows']['Age: 25'];
-      $expected['Singer']['rows']['27'] = $expected['Job: Singer']['rows']['Age: 27'];
-      $expected['Drummer'] = $expected['Job: Drummer'];
-      $expected['Drummer']['rows']['28'] = $expected['Job: Drummer']['rows']['Age: 28'];
-      unset($expected['Job: Singer']);
-      unset($expected['Singer']['rows']['Age: 25']);
-      unset($expected['Singer']['rows']['Age: 27']);
-      unset($expected['Job: Drummer']);
-      unset($expected['Drummer']['rows']['Age: 28']);
+      $new_expected = $expected;
+      $new_expected['Singer'] = $expected['Job: Singer'];
+      $new_expected['Singer']['rows']['25'] = $expected['Job: Singer']['rows']['Age: 25'];
+      $new_expected['Singer']['rows']['27'] = $expected['Job: Singer']['rows']['Age: 27'];
+      $new_expected['Drummer'] = $expected['Job: Drummer'];
+      $new_expected['Drummer']['rows']['28'] = $expected['Job: Drummer']['rows']['Age: 28'];
+      unset($new_expected['Job: Singer']);
+      unset($new_expected['Singer']['rows']['Age: 25']);
+      unset($new_expected['Singer']['rows']['Age: 27']);
+      unset($new_expected['Job: Drummer']);
+      unset($new_expected['Drummer']['rows']['Age: 28']);
 
-      $this->assertEqual($sets_new_value, $expected, 'The style plugins should proper group the results with grouping by the value.');
+      $this->assertEqual($sets_new_value, $new_expected, 'The style plugins should proper group the results with grouping by the value.');
     }
+
+    // Test that grouping works on fields having no label.
+    $fields['job']['label'] = '';
+    $view->destroy();
+    $view->setDisplay();
+    $view->initStyle();
+    $view->displayHandlers->get('default')->overrideOption('fields', $fields);
+    $view->style_plugin->options['grouping'] = array(
+      array('field' => 'job'),
+      array('field' => 'age'),
+    );
+
+    $this->executeView($view);
+
+    if ($stripped) {
+      $view->result[0]->views_test_data_job .= $rand1;
+      $view->result[1]->views_test_data_job .= $rand2;
+      $view->result[2]->views_test_data_job .= $rand3;
+      $view->style_plugin->options['grouping'][0] = array('field' => 'job', 'rendered' => TRUE, 'rendered_strip' => TRUE);
+      $view->style_plugin->options['grouping'][1] = array('field' => 'age', 'rendered' => TRUE, 'rendered_strip' => TRUE);
+    }
+
+    $sets_new_rendered = $view->style_plugin->renderGrouping($view->result, $view->style_plugin->options['grouping'], TRUE);
+
+    // Remove labels from expected results.
+    foreach ($expected as $job => $data) {
+      unset($expected[$job]);
+      $job = str_replace('Job: ', '', $job);
+      $data['group'] = $job;
+      $expected[$job] = $data;
+    }
+    $this->assertEqual($expected, $sets_new_rendered);
   }
 
   /**