diff --git a/classes/WDTSLanguageOptions.php b/classes/WDTSLanguageOptions.php
index 3928f29..8621af0 100644
--- a/classes/WDTSLanguageOptions.php
+++ b/classes/WDTSLanguageOptions.php
@@ -45,19 +45,31 @@ class WDTSLanguageOptions {
   function delete_language($code_to_delete) {
     $options = get_option($this->key);
 
-    $new_languages = array();
-    foreach ($options['languages'] as $code => $info) {
-      if ($code != $code_to_delete) { $new_languages[$code] = $info; }
+    $did_delete = false;
+    if (isset($options['languages'][$code_to_delete])) {
+      $did_delete = true;
+      unset($options['languages'][$code_to_delete]);
     }
-    $options['languages'] = $new_languages;
     
     update_option($this->key, $options);
+    return $did_delete;
   }
   
   function add_language($code, $info) {
-    $options = get_option($this->key);    
-    $options['languages'][$code] = $info;
+    $options = get_option($this->key);   
+    
+    $result = false;
+    if (!empty($code) && is_array($info)) {
+      if (!isset($options['languages'][$code])) {
+        if (!empty($info['name'])) {
+          $options['languages'][$code] = $info;
+          $result = true;
+        }        
+      }
+    }
+    
     update_option($this->key, $options);
+    return $result;
   }
   
   function rename_language($code_to_rename, $new_name) {
diff --git a/test/WDTSLanguageOptionsTest.php b/test/WDTSLanguageOptionsTest.php
index ad5a780..42a1048 100644
--- a/test/WDTSLanguageOptionsTest.php
+++ b/test/WDTSLanguageOptionsTest.php
@@ -46,39 +46,75 @@ class WDTSLanguageOptionsTest extends PHPUnit_Framework_TestCase {
     );
   }
   
-  function testDeleteLanguage() {
+  function providerTestDeleteLanguage() {
+    return array(
+      array('de', true),
+      array('fr', false)
+    ); 
+  }
+  
+  /**
+   * @dataProvider providerTestDeleteLanguage
+   */
+  function testDeleteLanguage($code, $expected_result) {
+    $check = array(
+      'en' => array('name' => 'English'),
+      'de' => array('name' => 'German')
+    );    
+
     update_option($this->l->key, array(
-      'languages' => array(
-        'en' => array('name' => 'English'),
-        'de' => array('name' => 'German')
-      )
+      'languages' => $check
     ));
     
-    $this->l->delete_language('en');
+    $this->assertEquals(
+      $expected_result,
+      $this->l->delete_language($code)
+    );
+    
+    if ($expected_result) {
+      unset($check[$code]);
+    }    
     
     $this->assertEquals(array(
-        'languages' => array(
-          'de' => array('name' => 'German')
-        )
-      ),
+      'languages' => $check      ),
       get_option($this->l->key)
     );
   }
 
-  function testAddLanguage() {
+  function providerTestAddLanguage() {
+    return array(
+      array('de', 'German', true),
+      array('de', '', false),
+      array('', 'German', false),
+      array('en', 'English', false),
+    ); 
+  }
+
+  /**
+   * @dataProvider providerTestAddLanguage
+   */
+  function testAddLanguage($code, $name, $expected_result) {
     update_option($this->l->key, array(
       'languages' => array(
         'en' => array('name' => 'English')
       )
     ));
     
-    $this->l->add_language('de', array('name' => 'German'));
+    $this->assertEquals(
+      $expected_result,
+      $this->l->add_language($code, array('name' => $name))
+    );
+    
+    $check = array(    
+      'en' => array('name' => 'English')
+    );
+    
+    if ($expected_result) {
+      $check[$code] = array('name' => $name); 
+    }
     
     $this->assertEquals(array(
-        'languages' => array(
-          'en' => array('name' => 'English'),
-          'de' => array('name' => 'German')
-        )
+        'languages' => $check
       ),
       get_option($this->l->key)
     );
@@ -105,7 +141,7 @@ class WDTSLanguageOptionsTest extends PHPUnit_Framework_TestCase {
 
     $this->assertEquals(
       $expected_result,
-      $result = $this->l->rename_language($code_to_rename, $new_name)
+      $this->l->rename_language($code_to_rename, $new_name)
     );
     
     $check = array(