diff --git a/metatag.module b/metatag.module
index c21e311..b42ab2e 100644
--- a/metatag.module
+++ b/metatag.module
@@ -1087,7 +1087,7 @@ function metatag_page_build(&$page) {
     drupal_alter('metatag_page_cache_cid_parts', $cid_parts);
 
     $cid = "output:{$instance}:" . hash('sha256', serialize($cid_parts));
-    
+
     if ($cache = cache_get($cid, 'cache_metatag')) {
       $metatags = $cache->data;
     }
@@ -1095,7 +1095,7 @@ function metatag_page_build(&$page) {
       $metatags = metatag_metatags_view($instance, array());
       cache_set($cid, $metatags, 'cache_metatag');
     }
-    
+
     $page['content']['metatags'][$instance] = $metatags;
   }
 
@@ -1471,11 +1471,11 @@ function metatag_config_instance_label($instance) {
 
   if (!isset($labels[$instance])) {
     $context = metatag_config_instance_info($instance);
-    $labels[$instance] = isset($context['label']) ? $context['label'] : t('Unknown');
+    $labels[$instance] = isset($context['label']) ? $context['label'] : t('Unknown (@instance)', array('@instance' => $instance));
     $parents = metatag_config_get_parent_instances($instance, FALSE);
     array_shift($parents);
     if (!empty($parents)) {
-      $labels[$instance] = metatag_config_instance_label(implode(':', $parents)) . ': ' . $labels[$instance];
+      $labels[$instance] = metatag_config_instance_label($parents[0]) . ': ' . $labels[$instance];
     }
   }
 
diff --git a/metatag.test b/metatag.test
index 49f6743..a943dea 100644
--- a/metatag.test
+++ b/metatag.test
@@ -71,4 +71,26 @@ class MetaTagsUnitTest extends MetaTagsTestHelper {
     );
   }
 
+  /**
+   * Test the metatag_config_instance_label() function.
+   */
+  public function testConfigLabels() {
+    $test_cases = array(
+      'node' => 'Node',
+      'node:article' => 'Node: Article',
+      'node:article:c' => 'Node: Article: Unknown (node:article:a)',
+      'node:b' => 'Node: Unknown (node:b)',
+      'node:b:c' => 'Node: Unknown (node:b): Unknown (node:b:c)',
+      'a' => 'Unknown (a)',
+      'a:b' => 'Unknown (a): Unknown (a:b)',
+      'a:b:c' => 'Unknown (a): Unknown (a:b): Unknown (a:b:c)',
+      'a:b:c:d' => 'Unknown (a): Unknown (a:b): Unknown (a:b:c): Unknown (a:b:c:d)',
+    );
+
+    foreach ($test_cases as $input => $expected_output) {
+      drupal_static_reset('metatag_config_instance_label');
+      $actual_output = metatag_config_instance_label($input);
+      $this->assertEqual($actual_output, $expected_output);
+    }
+  }
 }