diff --git a/UPGRADE-3.3.md b/UPGRADE-3.3.md
index 9ce7ee90d1..d58a018f2b 100644
--- a/UPGRADE-3.3.md
+++ b/UPGRADE-3.3.md
@@ -130,6 +130,34 @@ Finder
 
  * The `ExceptionInterface` has been deprecated and will be removed in 4.0.
 
+Form
+----
+
+ * Using the "choices" option in ``CountryType``, ``CurrencyType``, ``LanguageType``,
+   ``LocaleType``, and ``TimezoneType`` without overriding the ``choice_loader``
+   option has been deprecated and will be ignored in 4.0.
+   
+   Before:
+   ```php
+   $builder->add('custom_locales', LocaleType::class, array(
+       'choices' => $availableLocales,
+   ));
+   ```
+   
+   After:
+   ```php
+   $builder->add('custom_locales', LocaleType::class, array(
+       'choices' => $availableLocales,
+       'choice_loader' => null,
+   ));
+   // or
+   $builder->add('custom_locales', LocaleType::class, array(
+       'choice_loader' => new CallbackChoiceLoader(function () {
+           return $this->getAvailableLocales();
+       }),
+   ));
+   ```
+
 FrameworkBundle
 ---------------
 
diff --git a/UPGRADE-4.0.md b/UPGRADE-4.0.md
index a19b082c80..b9bf1295ee 100644
--- a/UPGRADE-4.0.md
+++ b/UPGRADE-4.0.md
@@ -193,6 +193,31 @@ Form
    }
    ```
 
+ * Using the "choices" option in ``CountryType``, ``CurrencyType``, ``LanguageType``,
+   ``LocaleType``, and ``TimezoneType`` without overriding the ``choice_loader``
+   option is now ignored.
+   
+   Before:
+   ```php
+   $builder->add('custom_locales', LocaleType::class, array(
+       'choices' => $availableLocales,
+   ));
+   ```
+   
+   After:
+   ```php
+   $builder->add('custom_locales', LocaleType::class, array(
+       'choices' => $availableLocales,
+       'choice_loader' => null,
+   ));
+   // or
+   $builder->add('custom_locales', LocaleType::class, array(
+       'choice_loader' => new CallbackChoiceLoader(function () {
+           return $this->getAvailableLocales();
+       }),
+   ));
+   ```
+
 FrameworkBundle
 ---------------
 
diff --git a/src/Symfony/Component/Form/CHANGELOG.md b/src/Symfony/Component/Form/CHANGELOG.md
index 1123119356..1c8936995c 100644
--- a/src/Symfony/Component/Form/CHANGELOG.md
+++ b/src/Symfony/Component/Form/CHANGELOG.md
@@ -4,6 +4,8 @@ CHANGELOG
 3.3.0
 -----
 
+ * deprecated using "choices" option in ``CountryType``, ``CurrencyType``, ``LanguageType``, ``LocaleType``, and
+   ``TimezoneType`` when "choice_loader" is not ``null``
  * added `Symfony\Component\Form\FormErrorIterator::findByCodes()`
  * added `getTypedExtensions`, `getTypes`, and `getTypeGuessers` to `Symfony\Component\Form\Test\FormIntegrationTestCase`
  * added `FormPass`
diff --git a/src/Symfony/Component/Form/Extension/Core/Type/CountryType.php b/src/Symfony/Component/Form/Extension/Core/Type/CountryType.php
index 6484a4c34f..02e8e09cdc 100644
--- a/src/Symfony/Component/Form/Extension/Core/Type/CountryType.php
+++ b/src/Symfony/Component/Form/Extension/Core/Type/CountryType.php
@@ -38,7 +38,13 @@ class CountryType extends AbstractType implements ChoiceLoaderInterface
     {
         $resolver->setDefaults(array(
             'choice_loader' => function (Options $options) {
-                return $options['choices'] ? null : $this;
+                if ($options['choices']) {
+                    @trigger_error(sprintf('Using the "choices" option in %s has been deprecated since version 3.3 and will be ignored in 4.0. Override the "choice_loader" option instead or set it to null.', __CLASS__), E_USER_DEPRECATED);
+
+                    return null;
+                }
+
+                return $this;
             },
             'choice_translation_domain' => false,
         ));
diff --git a/src/Symfony/Component/Form/Extension/Core/Type/CurrencyType.php b/src/Symfony/Component/Form/Extension/Core/Type/CurrencyType.php
index 4a8d3c4421..990235c10a 100644
--- a/src/Symfony/Component/Form/Extension/Core/Type/CurrencyType.php
+++ b/src/Symfony/Component/Form/Extension/Core/Type/CurrencyType.php
@@ -38,7 +38,13 @@ class CurrencyType extends AbstractType implements ChoiceLoaderInterface
     {
         $resolver->setDefaults(array(
             'choice_loader' => function (Options $options) {
-                return $options['choices'] ? null : $this;
+                if ($options['choices']) {
+                    @trigger_error(sprintf('Using the "choices" option in %s has been deprecated since version 3.3 and will be ignored in 4.0. Override the "choice_loader" option instead or set it to null.', __CLASS__), E_USER_DEPRECATED);
+
+                    return null;
+                }
+
+                return $this;
             },
             'choice_translation_domain' => false,
         ));
diff --git a/src/Symfony/Component/Form/Extension/Core/Type/LanguageType.php b/src/Symfony/Component/Form/Extension/Core/Type/LanguageType.php
index 3e62bdddce..2137c65a9e 100644
--- a/src/Symfony/Component/Form/Extension/Core/Type/LanguageType.php
+++ b/src/Symfony/Component/Form/Extension/Core/Type/LanguageType.php
@@ -38,7 +38,13 @@ class LanguageType extends AbstractType implements ChoiceLoaderInterface
     {
         $resolver->setDefaults(array(
             'choice_loader' => function (Options $options) {
-                return $options['choices'] ? null : $this;
+                if ($options['choices']) {
+                    @trigger_error(sprintf('Using the "choices" option in %s has been deprecated since version 3.3 and will be ignored in 4.0. Override the "choice_loader" option instead or set it to null.', __CLASS__), E_USER_DEPRECATED);
+
+                    return null;
+                }
+
+                return $this;
             },
             'choice_translation_domain' => false,
         ));
diff --git a/src/Symfony/Component/Form/Extension/Core/Type/LocaleType.php b/src/Symfony/Component/Form/Extension/Core/Type/LocaleType.php
index d5f191c0a2..38e62af060 100644
--- a/src/Symfony/Component/Form/Extension/Core/Type/LocaleType.php
+++ b/src/Symfony/Component/Form/Extension/Core/Type/LocaleType.php
@@ -38,7 +38,13 @@ class LocaleType extends AbstractType implements ChoiceLoaderInterface
     {
         $resolver->setDefaults(array(
             'choice_loader' => function (Options $options) {
-                return $options['choices'] ? null : $this;
+                if ($options['choices']) {
+                    @trigger_error(sprintf('Using the "choices" option in %s has been deprecated since version 3.3 and will be ignored in 4.0. Override the "choice_loader" option instead or set it to null.', __CLASS__), E_USER_DEPRECATED);
+
+                    return null;
+                }
+
+                return $this;
             },
             'choice_translation_domain' => false,
         ));
diff --git a/src/Symfony/Component/Form/Extension/Core/Type/TimezoneType.php b/src/Symfony/Component/Form/Extension/Core/Type/TimezoneType.php
index beb83dde4f..ffa86cb9aa 100644
--- a/src/Symfony/Component/Form/Extension/Core/Type/TimezoneType.php
+++ b/src/Symfony/Component/Form/Extension/Core/Type/TimezoneType.php
@@ -35,7 +35,13 @@ class TimezoneType extends AbstractType implements ChoiceLoaderInterface
     {
         $resolver->setDefaults(array(
             'choice_loader' => function (Options $options) {
-                return $options['choices'] ? null : $this;
+                if ($options['choices']) {
+                    @trigger_error(sprintf('Using the "choices" option in %s has been deprecated since version 3.3 and will be ignored in 4.0. Override the "choice_loader" option instead or set it to null.', __CLASS__), E_USER_DEPRECATED);
+
+                    return null;
+                }
+
+                return $this;
             },
             'choice_translation_domain' => false,
         ));
diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/Type/ExtendedChoiceTypeTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/Type/ExtendedChoiceTypeTest.php
index 6f9b4d128d..959ae488a1 100644
--- a/src/Symfony/Component/Form/Tests/Extension/Core/Type/ExtendedChoiceTypeTest.php
+++ b/src/Symfony/Component/Form/Tests/Extension/Core/Type/ExtendedChoiceTypeTest.php
@@ -14,13 +14,15 @@ namespace Symfony\Component\Form\Tests\Extension\Core\Type;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Form\Forms;
 use Symfony\Component\Form\Tests\Fixtures\ChoiceTypeExtension;
+use Symfony\Component\Form\Tests\Fixtures\LazyChoiceTypeExtension;
 
 class ExtendedChoiceTypeTest extends TestCase
 {
     /**
+     * @group legacy
      * @dataProvider provideTestedTypes
      */
-    public function testChoicesAreOverridden($type)
+    public function testLegacyChoicesAreOverridden($type)
     {
         $factory = Forms::createFormFactoryBuilder()
             ->addTypeExtension(new ChoiceTypeExtension($type))
@@ -36,6 +38,44 @@ class ExtendedChoiceTypeTest extends TestCase
         $this->assertSame('b', $choices[1]->value);
     }
 
+    /**
+     * @dataProvider provideTestedTypes
+     */
+    public function testChoicesAreOverridden($type)
+    {
+        $factory = Forms::createFormFactoryBuilder()
+            ->addTypeExtension(new ChoiceTypeExtension($type))
+            ->getFormFactory()
+        ;
+
+        $choices = $factory->create($type, null, array('choice_loader' => null))->createView()->vars['choices'];
+
+        $this->assertCount(2, $choices);
+        $this->assertSame('A', $choices[0]->label);
+        $this->assertSame('a', $choices[0]->value);
+        $this->assertSame('B', $choices[1]->label);
+        $this->assertSame('b', $choices[1]->value);
+    }
+
+    /**
+     * @dataProvider provideTestedTypes
+     */
+    public function testChoiceLoaderIsOverridden($type)
+    {
+        $factory = Forms::createFormFactoryBuilder()
+            ->addTypeExtension(new LazyChoiceTypeExtension($type))
+            ->getFormFactory()
+        ;
+
+        $choices = $factory->create($type)->createView()->vars['choices'];
+
+        $this->assertCount(2, $choices);
+        $this->assertSame('Lazy A', $choices[0]->label);
+        $this->assertSame('lazy_a', $choices[0]->value);
+        $this->assertSame('Lazy B', $choices[1]->label);
+        $this->assertSame('lazy_b', $choices[1]->value);
+    }
+
     public function provideTestedTypes()
     {
         yield array(CountryTypeTest::TESTED_TYPE);
diff --git a/src/Symfony/Component/Form/Tests/Fixtures/LazyChoiceTypeExtension.php b/src/Symfony/Component/Form/Tests/Fixtures/LazyChoiceTypeExtension.php
new file mode 100644
index 0000000000..133b8829e0
--- /dev/null
+++ b/src/Symfony/Component/Form/Tests/Fixtures/LazyChoiceTypeExtension.php
@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Form\Tests\Fixtures;
+
+use Symfony\Component\Form\AbstractTypeExtension;
+use Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader;
+use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
+use Symfony\Component\OptionsResolver\OptionsResolver;
+
+class LazyChoiceTypeExtension extends AbstractTypeExtension
+{
+    private $extendedType;
+
+    public function __construct($extendedType = ChoiceType::class)
+    {
+        $this->extendedType = $extendedType;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function configureOptions(OptionsResolver $resolver)
+    {
+        $resolver->setDefault('choice_loader', new CallbackChoiceLoader(function () {
+            return array(
+                'Lazy A' => 'lazy_a',
+                'Lazy B' => 'lazy_b',
+            );
+        }));
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getExtendedType()
+    {
+        return $this->extendedType;
+    }
+}