diff --git a/core/modules/language/language.module b/core/modules/language/language.module
index b0ad752..68404dc 100644
--- a/core/modules/language/language.module
+++ b/core/modules/language/language.module
@@ -863,7 +863,7 @@ function language_set_browser_drupal_langcode_mappings($mappings) {
 }
 
 /**
- * Updates locked system languages weight.
+ * Updates locked system language weights.
  *
  */
 function language_update_locked_weights() {
@@ -871,7 +871,7 @@ function language_update_locked_weights() {
   $max_weight = db_query('SELECT MAX(weight) FROM {language} WHERE locked = 0')->fetchField();
   // Loop locked languages to maintain the existing order.
   foreach (language_list(LANGUAGE_LOCKED) as $language) {
-    $max_weight ++;
+    $max_weight++;
     // Update system languages weight.
     db_update('language')
       ->fields(array('weight' => $max_weight))
diff --git a/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php b/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php
index e54b248..ebea58d 100644
--- a/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php
+++ b/core/modules/language/lib/Drupal/language/Tests/LanguageConfigurationTest.php
@@ -107,46 +107,54 @@ function testLanguageConfigurationWeight() {
     // User to add and remove language.
     $admin_user = $this->drupalCreateUser(array('administer languages', 'access administration pages'));
     $this->drupalLogin($admin_user);
-    $this->assertTrue($this->hasHighWeight(), 'System languages has high weight by default');
+    $this->checkConfigurableLanguageWeight();
 
     // Add predefined language.
     $edit = array(
       'predefined_langcode' => 'fr',
     );
     $this->drupalPost('admin/config/regional/language/add', $edit, 'Add language');
-    $this->assertTrue($this->hasHighWeight(), 'System languages has high weight after adding new language');
+    $this->checkConfigurableLanguageWeight('after adding new language');
 
     // Re-ordering languages.
     $edit = array(
-      'languages[en][weight]' => $this->getHighWeight() + 1,
+      'languages[en][weight]' => $this->getHighestConfigurableLanguageWeight() + 1,
     );
     $this->drupalPost('admin/config/regional/language', $edit, 'Save configuration');
-    $this->assertTrue($this->hasHighWeight(), 'System languages has high weight after re-ordering languages');
-
+    $this->checkConfigurableLanguageWeight('after re-ordering');
     // Remove predefined language.
     $edit = array(
       'confirm' => 1,
     );
     $this->drupalPost('admin/config/regional/language/delete/fr', $edit, 'Delete');
-    $this->assertTrue($this->hasHighWeight(), 'System languages has high weight after deleting a language');
+    $this->checkConfigurableLanguageWeight('after deleting a language');
   }
 
   /**
-   * Helper to check high weight of system languages;
+   * Helper to validate all system languages have higher weight.
+   *
+   * @param string $event
+   *   Event of check. e.g. reoder, save, delete.
    *
    * @return bool
    */
-  protected function hasHighWeight() {
-    $system_lang_weight = db_query('SELECT weight FROM {language} WHERE locked = 1 limit 1')->fetchField();
-    return $system_lang_weight >= $this->getHighWeight();
+  protected function checkConfigurableLanguageWeight($event = 'by default') {
+    // Reset language list.
+    drupal_static_reset('language_list');
+    $system_lang_weight = $this->getHighestConfigurableLanguageWeight();
+    $replacements = array('@event' => $event);
+    foreach (language_list(LANGUAGE_LOCKED) as $language) {
+      $replacements['%language'] = $language->name;
+      $this->assertTrue($language->weight >= $system_lang_weight, t('System language %language has higher weight than configurable languages @event', $replacements));
+    }
   }
 
   /**
-   * Helper to get high weight of unlocked languages list.
+   * Helper to get maximum weight of configurable (or unlocked) languages.
    *
    * @return int
    */
-  protected function getHighWeight(){
+  protected function getHighestConfigurableLanguageWeight(){
     return db_query('SELECT MAX(weight) FROM {language} WHERE locked = 0')->fetchField();
   }
 }