diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/FormPass.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/FormPass.php
index e1cb5c45c9..4a763a9e3c 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/FormPass.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/FormPass.php
@@ -30,7 +30,7 @@ class FormPass implements CompilerPassInterface
 
         $definition = $container->getDefinition('form.extension');
 
-        // Builds an array with service IDs as keys and tag aliases as values
+        // Builds an array with fully-qualified type class names as keys and service IDs as values
         $types = array();
 
         foreach ($container->findTaggedServiceIds('form.type') as $serviceId => $tag) {
@@ -46,12 +46,8 @@ class FormPass implements CompilerPassInterface
         foreach ($container->findTaggedServiceIds('form.type_extension') as $serviceId => $tag) {
             if (isset($tag[0]['extended_type'])) {
                 $extendedType = $tag[0]['extended_type'];
-            } elseif (isset($tag[0]['alias'])) {
-                @trigger_error('The alias option of the form.type_extension tag is deprecated since version 2.8 and will be removed in 3.0. Use the extended_type option instead.', E_USER_DEPRECATED);
-                $extendedType = $tag[0]['alias'];
             } else {
-                @trigger_error('The extended_type option of the form.type_extension tag is required since version 2.8 and will be removed in 3.0.', E_USER_DEPRECATED);
-                $extendedType = $serviceId;
+                throw new \InvalidArgumentException(sprintf('Tagged form type extension must have the extended type configured using the extended_type/extended-type attribute, none was configured for the "%s" service.', $serviceId));
             }
 
             $typeExtensions[$extendedType][] = $serviceId;
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml b/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml
index 0b2f0ee1f3..5d74391119 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/config/form.xml
@@ -50,97 +50,97 @@
 
         <service id="form.type.form" class="Symfony\Component\Form\Extension\Core\Type\FormType">
             <argument type="service" id="form.property_accessor" />
-            <tag name="form.type" alias="form" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.birthday" class="Symfony\Component\Form\Extension\Core\Type\BirthdayType">
-            <tag name="form.type" alias="birthday" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.checkbox" class="Symfony\Component\Form\Extension\Core\Type\CheckboxType">
-            <tag name="form.type" alias="checkbox" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.choice" class="Symfony\Component\Form\Extension\Core\Type\ChoiceType">
-            <tag name="form.type" alias="choice" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.collection" class="Symfony\Component\Form\Extension\Core\Type\CollectionType">
-            <tag name="form.type" alias="collection" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.country" class="Symfony\Component\Form\Extension\Core\Type\CountryType">
-            <tag name="form.type" alias="country" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.date" class="Symfony\Component\Form\Extension\Core\Type\DateType">
-            <tag name="form.type" alias="date" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.datetime" class="Symfony\Component\Form\Extension\Core\Type\DateTimeType">
-            <tag name="form.type" alias="datetime" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.email" class="Symfony\Component\Form\Extension\Core\Type\EmailType">
-            <tag name="form.type" alias="email" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.file" class="Symfony\Component\Form\Extension\Core\Type\FileType">
-            <tag name="form.type" alias="file" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.hidden" class="Symfony\Component\Form\Extension\Core\Type\HiddenType">
-            <tag name="form.type" alias="hidden" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.integer" class="Symfony\Component\Form\Extension\Core\Type\IntegerType">
-            <tag name="form.type" alias="integer" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.language" class="Symfony\Component\Form\Extension\Core\Type\LanguageType">
-            <tag name="form.type" alias="language" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.locale" class="Symfony\Component\Form\Extension\Core\Type\LocaleType">
-            <tag name="form.type" alias="locale" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.money" class="Symfony\Component\Form\Extension\Core\Type\MoneyType">
-            <tag name="form.type" alias="money" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.number" class="Symfony\Component\Form\Extension\Core\Type\NumberType">
-            <tag name="form.type" alias="number" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.password" class="Symfony\Component\Form\Extension\Core\Type\PasswordType">
-            <tag name="form.type" alias="password" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.percent" class="Symfony\Component\Form\Extension\Core\Type\PercentType">
-            <tag name="form.type" alias="percent" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.radio" class="Symfony\Component\Form\Extension\Core\Type\RadioType">
-            <tag name="form.type" alias="radio" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.range" class="Symfony\Component\Form\Extension\Core\Type\RangeType">
-            <tag name="form.type" alias="range" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.repeated" class="Symfony\Component\Form\Extension\Core\Type\RepeatedType">
-            <tag name="form.type" alias="repeated" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.search" class="Symfony\Component\Form\Extension\Core\Type\SearchType">
-            <tag name="form.type" alias="search" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.textarea" class="Symfony\Component\Form\Extension\Core\Type\TextareaType">
-            <tag name="form.type" alias="textarea" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.text" class="Symfony\Component\Form\Extension\Core\Type\TextType">
-            <tag name="form.type" alias="text" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.time" class="Symfony\Component\Form\Extension\Core\Type\TimeType">
-            <tag name="form.type" alias="time" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.timezone" class="Symfony\Component\Form\Extension\Core\Type\TimezoneType">
-            <tag name="form.type" alias="timezone" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.url" class="Symfony\Component\Form\Extension\Core\Type\UrlType">
-            <tag name="form.type" alias="url" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.button" class="Symfony\Component\Form\Extension\Core\Type\ButtonType">
-            <tag name="form.type" alias="button" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.submit" class="Symfony\Component\Form\Extension\Core\Type\SubmitType">
-            <tag name="form.type" alias="submit" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.reset" class="Symfony\Component\Form\Extension\Core\Type\ResetType">
-            <tag name="form.type" alias="reset" />
+            <tag name="form.type" />
         </service>
         <service id="form.type.currency" class="Symfony\Component\Form\Extension\Core\Type\CurrencyType">
-            <tag name="form.type" alias="currency" />
+            <tag name="form.type" />
         </service>
 
         <!-- FormTypeHttpFoundationExtension -->
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/FormPassTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/FormPassTest.php
index 29cefc7104..54dcc928f3 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/FormPassTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/FormPassTest.php
@@ -45,14 +45,9 @@ class FormPassTest extends \PHPUnit_Framework_TestCase
             array(),
         ));
 
-        $definition1 = new Definition(__CLASS__.'_Type1');
-        $definition1->addTag('form.type');
-        $definition2 = new Definition(__CLASS__.'_Type2');
-        $definition2->addTag('form.type');
-
         $container->setDefinition('form.extension', $extDefinition);
-        $container->setDefinition('my.type1', $definition1);
-        $container->setDefinition('my.type2', $definition2);
+        $container->register('my.type1', __CLASS__.'_Type1')->addTag('form.type');
+        $container->register('my.type2', __CLASS__.'_Type2')->addTag('form.type');
 
         $container->compile();
 
@@ -100,9 +95,10 @@ class FormPassTest extends \PHPUnit_Framework_TestCase
     }
 
     /**
-     * @group legacy
+     * @expectedException \InvalidArgumentException
+     * @expectedExceptionMessage extended-type attribute, none was configured for the "my.type_extension" service
      */
-    public function testAliasOptionForTaggedTypeExtensions()
+    public function testAddTaggedFormTypeExtensionWithoutExtendedTypeAttribute()
     {
         $container = new ContainerBuilder();
         $container->addCompilerPass(new FormPass());
@@ -115,23 +111,10 @@ class FormPassTest extends \PHPUnit_Framework_TestCase
         ));
 
         $container->setDefinition('form.extension', $extDefinition);
-        $container->register('my.type_extension1', 'stdClass')
-            ->addTag('form.type_extension', array('alias' => 'type1'));
-        $container->register('my.type_extension2', 'stdClass')
-            ->addTag('form.type_extension', array('alias' => 'type2'));
+        $container->register('my.type_extension', 'stdClass')
+            ->addTag('form.type_extension');
 
         $container->compile();
-
-        $extDefinition = $container->getDefinition('form.extension');
-
-        $this->assertSame(array(
-            'type1' => array(
-                'my.type_extension1',
-            ),
-            'type2' => array(
-                'my.type_extension2',
-            ),
-        ), $extDefinition->getArgument(2));
     }
 
     public function testAddTaggedGuessers()