diff --git a/src/Symfony/Component/DependencyInjection/Argument/ServiceLocatorArgument.php b/src/Symfony/Component/DependencyInjection/Argument/ServiceLocatorArgument.php
index 8214f8bb3a..fcbf478c62 100644
--- a/src/Symfony/Component/DependencyInjection/Argument/ServiceLocatorArgument.php
+++ b/src/Symfony/Component/DependencyInjection/Argument/ServiceLocatorArgument.php
@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\DependencyInjection\Argument;
 
+use Symfony\Component\DependencyInjection\Reference;
+
 /**
  * Represents a closure acting as a service locator.
  *
@@ -19,4 +21,24 @@ namespace Symfony\Component\DependencyInjection\Argument;
 class ServiceLocatorArgument implements ArgumentInterface
 {
     use ReferenceSetArgumentTrait;
+
+    private $taggedIteratorArgument;
+
+    /**
+     * @param Reference[]|TaggedIteratorArgument $values
+     */
+    public function __construct($values = [])
+    {
+        if ($values instanceof TaggedIteratorArgument) {
+            $this->taggedIteratorArgument = $values;
+            $this->values = [];
+        } else {
+            $this->setValues($values);
+        }
+    }
+
+    public function getTaggedIteratorArgument(): ?TaggedIteratorArgument
+    {
+        return $this->taggedIteratorArgument;
+    }
 }
diff --git a/src/Symfony/Component/DependencyInjection/Argument/TaggedIteratorArgument.php b/src/Symfony/Component/DependencyInjection/Argument/TaggedIteratorArgument.php
index fabfb00451..a3099686d1 100644
--- a/src/Symfony/Component/DependencyInjection/Argument/TaggedIteratorArgument.php
+++ b/src/Symfony/Component/DependencyInjection/Argument/TaggedIteratorArgument.php
@@ -23,8 +23,6 @@ class TaggedIteratorArgument extends IteratorArgument
     private $defaultIndexMethod;
 
     /**
-     * TaggedIteratorArgument constructor.
-     *
      * @param string      $tag                The name of the tag identifying the target services
      * @param string|null $indexAttribute     The name of the attribute that defines the key referencing each service in the tagged collection
      * @param string|null $defaultIndexMethod The static method that should be called to get each service's key when their tag doesn't define the previous attribute
diff --git a/src/Symfony/Component/DependencyInjection/CHANGELOG.md b/src/Symfony/Component/DependencyInjection/CHANGELOG.md
index 7390e4289f..c8ef90f5bc 100644
--- a/src/Symfony/Component/DependencyInjection/CHANGELOG.md
+++ b/src/Symfony/Component/DependencyInjection/CHANGELOG.md
@@ -9,6 +9,7 @@ CHANGELOG
  * added support for deprecating aliases
  * made `ContainerParametersResource` final and not implement `Serializable` anymore
  * added ability to define an index for a tagged collection
+ * added ability to define an index for services in an injected service locator argument
 
 4.2.0
 -----
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php b/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php
index e335307482..2030d3774c 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/ServiceLocatorTagPass.php
@@ -27,11 +27,18 @@ use Symfony\Component\DependencyInjection\ServiceLocator;
  */
 final class ServiceLocatorTagPass extends AbstractRecursivePass
 {
+    use PriorityTaggedServiceTrait;
+
     protected function processValue($value, $isRoot = false)
     {
         if ($value instanceof ServiceLocatorArgument) {
+            if ($value->getTaggedIteratorArgument()) {
+                $value->setValues($this->findAndSortTaggedServices($value->getTaggedIteratorArgument(), $this->container));
+            }
+
             return self::register($this->container, $value->getValues());
         }
+
         if (!$value instanceof Definition || !$value->hasTag('container.service_locator')) {
             return parent::processValue($value, $isRoot);
         }
diff --git a/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php b/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php
index eb56becd8d..5b9edd0351 100644
--- a/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php
+++ b/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php
@@ -298,8 +298,18 @@ class XmlDumper extends Dumper
                 $element->setAttribute('type', 'iterator');
                 $this->convertParameters($value->getValues(), $type, $element, 'key');
             } elseif ($value instanceof ServiceLocatorArgument) {
-                $element->setAttribute('type', 'service_locator');
-                $this->convertParameters($value->getValues(), $type, $element, 'key');
+                if ($value->getTaggedIteratorArgument()) {
+                    $element->setAttribute('type', 'tagged_locator');
+                    $element->setAttribute('tag', $value->getTaggedIteratorArgument()->getTag());
+                    $element->setAttribute('index-by', $value->getTaggedIteratorArgument()->getIndexAttribute());
+
+                    if (null !== $value->getTaggedIteratorArgument()->getDefaultIndexMethod()) {
+                        $element->setAttribute('default-index-method', $value->getTaggedIteratorArgument()->getDefaultIndexMethod());
+                    }
+                } else {
+                    $element->setAttribute('type', 'service_locator');
+                    $this->convertParameters($value->getValues(), $type, $element, 'key');
+                }
             } elseif ($value instanceof Reference) {
                 $element->setAttribute('type', 'service');
                 $element->setAttribute('id', (string) $value);
diff --git a/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php b/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php
index 875ebbc0ab..b4c899379c 100644
--- a/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php
+++ b/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php
@@ -252,6 +252,18 @@ class YamlDumper extends Dumper
                 $tag = 'iterator';
             } elseif ($value instanceof ServiceLocatorArgument) {
                 $tag = 'service_locator';
+                if ($value->getTaggedIteratorArgument()) {
+                    $taggedValueContent = [
+                        'tag' => $value->getTaggedIteratorArgument()->getTag(),
+                        'index_by' => $value->getTaggedIteratorArgument()->getIndexAttribute(),
+                    ];
+
+                    if (null !== $value->getTaggedIteratorArgument()->getDefaultIndexMethod()) {
+                        $taggedValueContent['default_index_method'] = $value->getTaggedIteratorArgument()->getDefaultIndexMethod();
+                    }
+
+                    return new TaggedValue('tagged_locator', $taggedValueContent);
+                }
             } else {
                 throw new RuntimeException(sprintf('Unspecified Yaml tag for type "%s".', \get_class($value)));
             }
diff --git a/src/Symfony/Component/DependencyInjection/Loader/Configurator/ContainerConfigurator.php b/src/Symfony/Component/DependencyInjection/Loader/Configurator/ContainerConfigurator.php
index f75ba1be85..d4b03fc2c1 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/Configurator/ContainerConfigurator.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/Configurator/ContainerConfigurator.php
@@ -121,6 +121,14 @@ function tagged(string $tag, string $indexAttribute = null, string $defaultIndex
     return new TaggedIteratorArgument($tag, $indexAttribute, $defaultIndexMethod);
 }
 
+/**
+ * Creates a service locator by tag name.
+ */
+function tagged_locator(string $tag, string $indexAttribute, string $defaultIndexMethod = null): ServiceLocatorArgument
+{
+    return new ServiceLocatorArgument(new TaggedIteratorArgument($tag, $indexAttribute, $defaultIndexMethod));
+}
+
 /**
  * Creates an expression.
  */
diff --git a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
index b5e076888f..ced8b0142d 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
@@ -533,6 +533,13 @@ class XmlFileLoader extends FileLoader
                         throw new InvalidArgumentException(sprintf('Tag "<%s>" with type="service_locator" only accepts maps of type="service" references in "%s".', $name, $file));
                     }
                     break;
+                case 'tagged_locator':
+                    if (!$arg->getAttribute('tag') || !$arg->getAttribute('index-by')) {
+                        throw new InvalidArgumentException(sprintf('Tag "<%s>" with type="tagged_locator" has no or empty "tag" or "index-by" attributes in "%s".', $name, $file));
+                    }
+
+                    $arguments[$key] = new ServiceLocatorArgument(new TaggedIteratorArgument($arg->getAttribute('tag'), $arg->getAttribute('index-by'), $arg->getAttribute('default-index-method') ?: null));
+                    break;
                 case 'tagged':
                     if (!$arg->getAttribute('tag')) {
                         throw new InvalidArgumentException(sprintf('Tag "<%s>" with type="tagged" has no or empty "tag" attribute in "%s".', $name, $file));
diff --git a/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
index 06fcbb4a91..4d9da4e314 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
@@ -702,7 +702,9 @@ class YamlFileLoader extends FileLoader
                 if (!\is_array($argument)) {
                     throw new InvalidArgumentException(sprintf('"!service_locator" tag only accepts maps in "%s".', $file));
                 }
+
                 $argument = $this->resolveServices($argument, $file, $isParameter);
+
                 try {
                     return new ServiceLocatorArgument($argument);
                 } catch (InvalidArgumentException $e) {
@@ -724,6 +726,17 @@ class YamlFileLoader extends FileLoader
 
                 throw new InvalidArgumentException(sprintf('"!tagged" tags only accept a non empty string or an array with a key "tag" in "%s".', $file));
             }
+            if ('tagged_locator' === $value->getTag()) {
+                if (\is_array($argument) && isset($argument['tag'], $argument['index_by']) && $argument['tag'] && $argument['index_by']) {
+                    if ($diff = array_diff(array_keys($argument), ['tag', 'index_by', 'default_index_method'])) {
+                        throw new InvalidArgumentException(sprintf('"!tagged_locator" tag contains unsupported key "%s"; supported ones are "tag", "index_by" and "default_index_method".', implode('"", "', $diff)));
+                    }
+
+                    return new ServiceLocatorArgument(new TaggedIteratorArgument($argument['tag'], $argument['index_by'], $argument['default_index_method'] ?? null));
+                }
+
+                throw new InvalidArgumentException(sprintf('"!tagged_locator" tags only accept an array with at least keys "tag" and "index_by" in "%s".', $file));
+            }
             if ('service' === $value->getTag()) {
                 if ($isParameter) {
                     throw new InvalidArgumentException(sprintf('Using an anonymous service in a parameter is not allowed in "%s".', $file));
diff --git a/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd b/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd
index b14ffc8dcd..841e807943 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd
+++ b/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd
@@ -264,6 +264,7 @@
       <xsd:enumeration value="iterator" />
       <xsd:enumeration value="service_locator" />
       <xsd:enumeration value="tagged" />
+      <xsd:enumeration value="tagged_locator" />
     </xsd:restriction>
   </xsd:simpleType>
 
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php
index 1ba0a53eaa..a2bbbe20cf 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/IntegrationTest.php
@@ -14,10 +14,12 @@ namespace Symfony\Component\DependencyInjection\Tests\Compiler;
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\DependencyInjection\Alias;
+use Symfony\Component\DependencyInjection\Argument\ServiceLocatorArgument;
 use Symfony\Component\DependencyInjection\Argument\TaggedIteratorArgument;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\DependencyInjection\ServiceLocator;
 use Symfony\Component\DependencyInjection\ServiceSubscriberInterface;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\BarTagClass;
 use Symfony\Component\DependencyInjection\Tests\Fixtures\FooBarTaggedClass;
@@ -242,15 +244,15 @@ class IntegrationTest extends TestCase
     public function testTaggedServiceWithIndexAttribute()
     {
         $container = new ContainerBuilder();
-        $container->register(BarTagClass::class, BarTagClass::class)
+        $container->register(BarTagClass::class)
             ->setPublic(true)
             ->addTag('foo_bar', ['foo' => 'bar'])
         ;
-        $container->register(FooTagClass::class, FooTagClass::class)
+        $container->register(FooTagClass::class)
             ->setPublic(true)
             ->addTag('foo_bar')
         ;
-        $container->register(FooBarTaggedClass::class, FooBarTaggedClass::class)
+        $container->register(FooBarTaggedClass::class)
             ->addArgument(new TaggedIteratorArgument('foo_bar', 'foo'))
             ->setPublic(true)
         ;
@@ -266,15 +268,15 @@ class IntegrationTest extends TestCase
     public function testTaggedServiceWithIndexAttributeAndDefaultMethod()
     {
         $container = new ContainerBuilder();
-        $container->register(BarTagClass::class, BarTagClass::class)
+        $container->register(BarTagClass::class)
             ->setPublic(true)
             ->addTag('foo_bar')
         ;
-        $container->register(FooTagClass::class, FooTagClass::class)
+        $container->register(FooTagClass::class)
             ->setPublic(true)
             ->addTag('foo_bar', ['foo' => 'foo'])
         ;
-        $container->register(FooBarTaggedClass::class, FooBarTaggedClass::class)
+        $container->register(FooBarTaggedClass::class)
             ->addArgument(new TaggedIteratorArgument('foo_bar', 'foo', 'getFooBar'))
             ->setPublic(true)
         ;
@@ -286,6 +288,68 @@ class IntegrationTest extends TestCase
         $param = iterator_to_array($s->getParam()->getIterator());
         $this->assertSame(['bar_tab_class_with_defaultmethod' => $container->get(BarTagClass::class), 'foo' => $container->get(FooTagClass::class)], $param);
     }
+
+    public function testTaggedServiceLocatorWithIndexAttribute()
+    {
+        $container = new ContainerBuilder();
+        $container->register(BarTagClass::class)
+            ->setPublic(true)
+            ->addTag('foo_bar', ['foo' => 'bar'])
+        ;
+        $container->register(FooTagClass::class)
+            ->setPublic(true)
+            ->addTag('foo_bar')
+        ;
+        $container->register(FooBarTaggedClass::class)
+            ->addArgument(new ServiceLocatorArgument(new TaggedIteratorArgument('foo_bar', 'foo')))
+            ->setPublic(true)
+        ;
+
+        $container->compile();
+
+        $s = $container->get(FooBarTaggedClass::class);
+
+        /** @var ServiceLocator $serviceLocator */
+        $serviceLocator = $s->getParam();
+        $this->assertTrue($s->getParam() instanceof ServiceLocator, sprintf('Wrong instance, should be an instance of ServiceLocator, %s given', \is_object($serviceLocator) ? \get_class($serviceLocator) : \gettype($serviceLocator)));
+
+        $same = [
+            'bar' => $serviceLocator->get('bar'),
+            'foo_tag_class' => $serviceLocator->get('foo_tag_class'),
+        ];
+        $this->assertSame(['bar' => $container->get(BarTagClass::class), 'foo_tag_class' => $container->get(FooTagClass::class)], $same);
+    }
+
+    public function testTaggedServiceLocatorWithIndexAttributeAndDefaultMethod()
+    {
+        $container = new ContainerBuilder();
+        $container->register(BarTagClass::class)
+            ->setPublic(true)
+            ->addTag('foo_bar')
+        ;
+        $container->register(FooTagClass::class)
+            ->setPublic(true)
+            ->addTag('foo_bar', ['foo' => 'foo'])
+        ;
+        $container->register(FooBarTaggedClass::class)
+            ->addArgument(new ServiceLocatorArgument(new TaggedIteratorArgument('foo_bar', 'foo', 'getFooBar')))
+            ->setPublic(true)
+        ;
+
+        $container->compile();
+
+        $s = $container->get(FooBarTaggedClass::class);
+
+        /** @var ServiceLocator $serviceLocator */
+        $serviceLocator = $s->getParam();
+        $this->assertTrue($s->getParam() instanceof ServiceLocator, sprintf('Wrong instance, should be an instance of ServiceLocator, %s given', \is_object($serviceLocator) ? \get_class($serviceLocator) : \gettype($serviceLocator)));
+
+        $same = [
+            'bar_tab_class_with_defaultmethod' => $serviceLocator->get('bar_tab_class_with_defaultmethod'),
+            'foo' => $serviceLocator->get('foo'),
+        ];
+        $this->assertSame(['bar_tab_class_with_defaultmethod' => $container->get(BarTagClass::class), 'foo' => $container->get(FooTagClass::class)], $same);
+    }
 }
 
 class ServiceSubscriberStub implements ServiceSubscriberInterface
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/PriorityTaggedServiceTraitTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/PriorityTaggedServiceTraitTest.php
index 57ca9af427..adf9696acd 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/PriorityTaggedServiceTraitTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/PriorityTaggedServiceTraitTest.php
@@ -93,6 +93,6 @@ class PriorityTaggedServiceTraitImplementation
 
     public function test($tagName, ContainerBuilder $container)
     {
-        return $this->findAndSortTaggedServices($tagName, $container);
+        return self::findAndSortTaggedServices($tagName, $container);
     }
 }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php b/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php
index 2c5615bc69..cc80a69455 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php
@@ -13,6 +13,7 @@ namespace Symfony\Component\DependencyInjection\Tests\Dumper;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\FileLocator;
+use Symfony\Component\DependencyInjection\Argument\ServiceLocatorArgument;
 use Symfony\Component\DependencyInjection\Argument\TaggedIteratorArgument;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -201,13 +202,18 @@ class XmlDumperTest extends TestCase
         $this->assertStringEqualsFile(self::$fixturesPath.'/xml/services_dump_load.xml', $dumper->dump());
     }
 
-    public function testTaggedArgument()
+    public function testTaggedArguments()
     {
+        $taggedIterator = new TaggedIteratorArgument('foo_tag', 'barfoo', 'foobar');
         $container = new ContainerBuilder();
         $container->register('foo', 'Foo')->addTag('foo_tag');
         $container->register('foo_tagged_iterator', 'Bar')
             ->setPublic(true)
-            ->addArgument(new TaggedIteratorArgument('foo_tag', 'barfoo', 'foobar'))
+            ->addArgument($taggedIterator)
+        ;
+        $container->register('foo_tagged_locator', 'Bar')
+            ->setPublic(true)
+            ->addArgument(new ServiceLocatorArgument($taggedIterator))
         ;
 
         $dumper = new XmlDumper($container);
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Dumper/YamlDumperTest.php b/src/Symfony/Component/DependencyInjection/Tests/Dumper/YamlDumperTest.php
index 61a1aec510..72901c855e 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Dumper/YamlDumperTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Dumper/YamlDumperTest.php
@@ -13,6 +13,7 @@ namespace Symfony\Component\DependencyInjection\Tests\Dumper;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\FileLocator;
+use Symfony\Component\DependencyInjection\Argument\ServiceLocatorArgument;
 use Symfony\Component\DependencyInjection\Argument\TaggedIteratorArgument;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -96,11 +97,13 @@ class YamlDumperTest extends TestCase
         $this->assertStringEqualsFile(self::$fixturesPath.'/yaml/services_inline.yml', $dumper->dump());
     }
 
-    public function testTaggedArgument()
+    public function testTaggedArguments()
     {
+        $taggedIterator = new TaggedIteratorArgument('foo', 'barfoo', 'foobar');
         $container = new ContainerBuilder();
         $container->register('foo_service', 'Foo')->addTag('foo');
-        $container->register('foo_service_tagged', 'Bar')->addArgument(new TaggedIteratorArgument('foo', 'barfoo', 'foobar'));
+        $container->register('foo_service_tagged_iterator', 'Bar')->addArgument($taggedIterator);
+        $container->register('foo_service_tagged_locator', 'Bar')->addArgument(new ServiceLocatorArgument($taggedIterator));
 
         $dumper = new YamlDumper($container);
         $this->assertStringEqualsFile(self::$fixturesPath.'/yaml/services_with_tagged_argument.yml', $dumper->dump());
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services_with_tagged_arguments.xml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services_with_tagged_arguments.xml
index e979d5fc9b..e3e51d352d 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services_with_tagged_arguments.xml
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services_with_tagged_arguments.xml
@@ -8,6 +8,9 @@
     <service id="foo_tagged_iterator" class="Bar" public="true">
       <argument type="tagged" tag="foo_tag" index-by="barfoo" default-index-method="foobar"/>
     </service>
+    <service id="foo_tagged_locator" class="Bar" public="true">
+      <argument type="tagged_locator" tag="foo_tag" index-by="barfoo" default-index-method="foobar"/>
+    </service>
     <service id="Psr\Container\ContainerInterface" alias="service_container" public="false"/>
     <service id="Symfony\Component\DependencyInjection\ContainerInterface" alias="service_container" public="false"/>
   </services>
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_with_tagged_argument.yml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_with_tagged_argument.yml
index bf7cf06930..5e071d3278 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_with_tagged_argument.yml
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services_with_tagged_argument.yml
@@ -8,9 +8,12 @@ services:
         class: Foo
         tags:
             - { name: foo }
-    foo_service_tagged:
+    foo_service_tagged_iterator:
         class: Bar
         arguments: [!tagged { tag: foo, index_by: barfoo, default_index_method: foobar }]
+    foo_service_tagged_locator:
+        class: Bar
+        arguments: [!tagged_locator { tag: foo, index_by: barfoo, default_index_method: foobar }]
     Psr\Container\ContainerInterface:
         alias: service_container
         public: false
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
index 20c80258e2..3e326ed85a 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
@@ -18,6 +18,7 @@ use Symfony\Component\Config\Resource\FileResource;
 use Symfony\Component\Config\Resource\GlobResource;
 use Symfony\Component\DependencyInjection\Argument\BoundArgument;
 use Symfony\Component\DependencyInjection\Argument\IteratorArgument;
+use Symfony\Component\DependencyInjection\Argument\ServiceLocatorArgument;
 use Symfony\Component\DependencyInjection\Argument\TaggedIteratorArgument;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
@@ -324,7 +325,11 @@ class XmlFileLoaderTest extends TestCase
 
         $this->assertCount(1, $container->getDefinition('foo')->getTag('foo_tag'));
         $this->assertCount(1, $container->getDefinition('foo_tagged_iterator')->getArguments());
-        $this->assertEquals(new TaggedIteratorArgument('foo_tag', 'barfoo', 'foobar'), $container->getDefinition('foo_tagged_iterator')->getArgument(0));
+        $this->assertCount(1, $container->getDefinition('foo_tagged_locator')->getArguments());
+
+        $taggedIterator = new TaggedIteratorArgument('foo_tag', 'barfoo', 'foobar');
+        $this->assertEquals($taggedIterator, $container->getDefinition('foo_tagged_iterator')->getArgument(0));
+        $this->assertEquals(new ServiceLocatorArgument($taggedIterator), $container->getDefinition('foo_tagged_locator')->getArgument(0));
     }
 
     /**
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
index 7870a521a9..0da99f437b 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
@@ -18,6 +18,7 @@ use Symfony\Component\Config\Resource\FileResource;
 use Symfony\Component\Config\Resource\GlobResource;
 use Symfony\Component\DependencyInjection\Argument\BoundArgument;
 use Symfony\Component\DependencyInjection\Argument\IteratorArgument;
+use Symfony\Component\DependencyInjection\Argument\ServiceLocatorArgument;
 use Symfony\Component\DependencyInjection\Argument\TaggedIteratorArgument;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Loader\IniFileLoader;
@@ -287,8 +288,12 @@ class YamlFileLoaderTest extends TestCase
         $loader->load('services_with_tagged_argument.yml');
 
         $this->assertCount(1, $container->getDefinition('foo_service')->getTag('foo'));
-        $this->assertCount(1, $container->getDefinition('foo_service_tagged')->getArguments());
-        $this->assertEquals(new TaggedIteratorArgument('foo', 'barfoo', 'foobar'), $container->getDefinition('foo_service_tagged')->getArgument(0));
+        $this->assertCount(1, $container->getDefinition('foo_service_tagged_iterator')->getArguments());
+        $this->assertCount(1, $container->getDefinition('foo_service_tagged_locator')->getArguments());
+
+        $taggedIterator = new TaggedIteratorArgument('foo', 'barfoo', 'foobar');
+        $this->assertEquals($taggedIterator, $container->getDefinition('foo_service_tagged_iterator')->getArgument(0));
+        $this->assertEquals(new ServiceLocatorArgument($taggedIterator), $container->getDefinition('foo_service_tagged_locator')->getArgument(0));
     }
 
     public function testNameOnlyTagsAreAllowedAsString()