diff --git a/bundles/configuration.rst b/bundles/configuration.rst
index 40eaf331d4f..dac9550a161 100644
--- a/bundles/configuration.rst
+++ b/bundles/configuration.rst
@@ -64,7 +64,7 @@ can add some configuration that looks like this:
     .. code-block:: xml
 
         <!-- config/packages/acme_social.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:acme-social="http://example.org/schema/dic/acme_social"
@@ -416,7 +416,7 @@ Assuming the XSD file is called ``hello-1.0.xsd``, the schema location will be
 .. code-block:: xml
 
     <!-- config/packages/acme_hello.xml -->
-    <?xml version="1.0" ?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <container xmlns="http://symfony.com/schema/dic/services"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns:acme-hello="http://acme_company.com/schema/dic/hello"
diff --git a/components/dependency_injection/compilation.rst b/components/dependency_injection/compilation.rst
index 55725be8da0..d7284046b82 100644
--- a/components/dependency_injection/compilation.rst
+++ b/components/dependency_injection/compilation.rst
@@ -197,7 +197,7 @@ The XML version of the config would then look like this:
 
 .. code-block:: xml
 
-    <?xml version="1.0" ?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <container xmlns="http://symfony.com/schema/dic/services"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns:acme_demo="http://www.example.com/symfony/schema/"
diff --git a/components/dom_crawler.rst b/components/dom_crawler.rst
index b1dda3d42f7..93aba242eaf 100644
--- a/components/dom_crawler.rst
+++ b/components/dom_crawler.rst
@@ -126,7 +126,7 @@ Consider the XML below:
 
 .. code-block:: xml
 
-    <?xml version="1.0" encoding="UTF-8"?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <entry
         xmlns="http://www.w3.org/2005/Atom"
         xmlns:media="http://search.yahoo.com/mrss/"
diff --git a/components/serializer.rst b/components/serializer.rst
index 84c8ecb8a36..783f293e83d 100644
--- a/components/serializer.rst
+++ b/components/serializer.rst
@@ -331,7 +331,7 @@ Then, create your groups definition:
 
     .. code-block:: xml
 
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <serializer xmlns="http://symfony.com/schema/dic/serializer-mapping"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/serializer-mapping
@@ -613,7 +613,7 @@ defines a ``Person`` entity with a ``firstName`` property:
 
     .. code-block:: xml
 
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <serializer xmlns="http://symfony.com/schema/dic/serializer-mapping"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/serializer-mapping
@@ -903,7 +903,7 @@ For example, take an object normalized as following::
 
 The ``XmlEncoder`` will encode this object like that::
 
-    <?xml version="1.0"?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <response>
         <foo>1</foo>
         <foo>2</foo>
@@ -1187,7 +1187,7 @@ Here, we set it to 2 for the ``$child`` property:
 
     .. code-block:: xml
 
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <serializer xmlns="http://symfony.com/schema/dic/serializer-mapping"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/serializer-mapping
@@ -1505,7 +1505,7 @@ and ``BitBucketCodeRepository`` classes:
 
     .. code-block:: xml
 
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <serializer xmlns="http://symfony.com/schema/dic/serializer-mapping"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/serializer-mapping
diff --git a/configuration/override_dir_structure.rst b/configuration/override_dir_structure.rst
index ece722f6f27..e832daeb030 100644
--- a/configuration/override_dir_structure.rst
+++ b/configuration/override_dir_structure.rst
@@ -114,7 +114,7 @@ for multiple directories):
     .. code-block:: xml
 
         <!-- config/packages/twig.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:twig="http://symfony.com/schema/dic/twig"
@@ -156,7 +156,7 @@ configuration option to define your own translations directory (use :ref:`framew
     .. code-block:: xml
 
         <!-- config/packages/translation.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:twig="http://symfony.com/schema/dic/twig"
diff --git a/create_framework/unit_testing.rst b/create_framework/unit_testing.rst
index 099ada7e704..cff94d1087b 100644
--- a/create_framework/unit_testing.rst
+++ b/create_framework/unit_testing.rst
@@ -13,7 +13,7 @@ using `PHPUnit`_. Create a PHPUnit configuration file in
 
 .. code-block:: xml
 
-    <?xml version="1.0" encoding="UTF-8"?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <phpunit
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/5.1/phpunit.xsd"
@@ -49,7 +49,7 @@ resolver. Modify the framework to make use of them::
     namespace Simplex;
 
     // ...
-    
+
     use Calendar\Controller\LeapYearController;
     use Symfony\Component\HttpKernel\Controller\ArgumentResolverInterface;
     use Symfony\Component\HttpKernel\Controller\ControllerResolverInterface;
diff --git a/doctrine/events.rst b/doctrine/events.rst
index 30b48856c13..8acde6359ed 100644
--- a/doctrine/events.rst
+++ b/doctrine/events.rst
@@ -176,7 +176,7 @@ with the ``doctrine.event_listener`` tag:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:doctrine="http://symfony.com/schema/dic/doctrine">
             <services>
@@ -283,7 +283,7 @@ with the ``doctrine.orm.entity_listener`` tag:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:doctrine="http://symfony.com/schema/dic/doctrine">
             <services>
@@ -425,7 +425,7 @@ with the ``doctrine.event_subscriber`` tag:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:doctrine="http://symfony.com/schema/dic/doctrine">
             <services>
@@ -464,7 +464,7 @@ can do it in the service configuration:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:doctrine="http://symfony.com/schema/dic/doctrine">
             <services>
diff --git a/doctrine/multiple_entity_managers.rst b/doctrine/multiple_entity_managers.rst
index 32e5a979cdb..e55165bc458 100644
--- a/doctrine/multiple_entity_managers.rst
+++ b/doctrine/multiple_entity_managers.rst
@@ -71,7 +71,7 @@ The following configuration code shows how you can configure two entity managers
     .. code-block:: xml
 
         <!-- config/packages/doctrine.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:doctrine="http://symfony.com/schema/dic/doctrine"
diff --git a/forms.rst b/forms.rst
index 6f244fd7d1c..289e1a194b0 100644
--- a/forms.rst
+++ b/forms.rst
@@ -521,7 +521,7 @@ object.
     .. code-block:: xml
 
         <!-- config/validator/validation.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <constraint-mapping xmlns="http://symfony.com/schema/dic/constraint-mapping"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/constraint-mapping
diff --git a/reference/configuration/security.rst b/reference/configuration/security.rst
index 399794e2402..7a2b23b0d2d 100644
--- a/reference/configuration/security.rst
+++ b/reference/configuration/security.rst
@@ -358,7 +358,7 @@ application:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/routing.rst b/routing.rst
index a0617bfb31e..fefe3a190a3 100644
--- a/routing.rst
+++ b/routing.rst
@@ -1996,7 +1996,7 @@ generate URLs. This context can be configured globally for all commands:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
@@ -2111,7 +2111,7 @@ method) or globally with these configuration parameters:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
diff --git a/routing/custom_route_loader.rst b/routing/custom_route_loader.rst
index b438ed7bb11..16a445d96a6 100644
--- a/routing/custom_route_loader.rst
+++ b/routing/custom_route_loader.rst
@@ -318,7 +318,7 @@ Now define a service for the ``ExtraLoader``:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
diff --git a/security.rst b/security.rst
index a582997801b..c0439086b76 100644
--- a/security.rst
+++ b/security.rst
@@ -116,7 +116,7 @@ Fortunately, the ``make:user`` command already configured one for you in your
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -184,7 +184,7 @@ command will pre-configure this for you:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -298,7 +298,7 @@ important section is ``firewalls``:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -523,7 +523,7 @@ start with ``/admin``, you can:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -599,7 +599,7 @@ the list and stops when it finds the first match:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -853,7 +853,7 @@ To enable logging out, activate the  ``logout`` config parameter under your fire
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -970,7 +970,7 @@ rules by creating a role hierarchy:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/access_control.rst b/security/access_control.rst
index 53d216c8ce2..68c659095b2 100644
--- a/security/access_control.rst
+++ b/security/access_control.rst
@@ -50,7 +50,7 @@ Take the following ``access_control`` entries as an example:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -222,7 +222,7 @@ pattern so that it is only accessible by requests from the local server itself:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -309,7 +309,7 @@ key:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -385,7 +385,7 @@ access those URLs via a specific port. This could be useful for example for
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -436,7 +436,7 @@ the user will be redirected to ``https``:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/access_denied_handler.rst b/security/access_denied_handler.rst
index 42ee7fe5dd9..8db53e89421 100644
--- a/security/access_denied_handler.rst
+++ b/security/access_denied_handler.rst
@@ -73,7 +73,7 @@ Now, configure this service ID as the entry point for the firewall:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -150,7 +150,7 @@ configure it under your firewall:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/auth_providers.rst b/security/auth_providers.rst
index f5ec3723c7b..e68e9849685 100644
--- a/security/auth_providers.rst
+++ b/security/auth_providers.rst
@@ -52,7 +52,7 @@ To support HTTP Basic authentication, add the ``http_basic`` key to your firewal
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -118,7 +118,7 @@ Enable the x509 authentication for a particular firewall in the security configu
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -197,7 +197,7 @@ corresponding firewall in your security configuration:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" ?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:srv="http://symfony.com/schema/dic/services">
 
diff --git a/security/custom_authentication_provider.rst b/security/custom_authentication_provider.rst
index 920c8315f05..1b141b0f85f 100644
--- a/security/custom_authentication_provider.rst
+++ b/security/custom_authentication_provider.rst
@@ -483,7 +483,7 @@ You are finished! You can now define parts of your app as under WSSE protection.
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -563,7 +563,7 @@ in order to put it to use::
 
     // src/DependencyInjection/Security/Factory/WsseFactory.php
     namespace App\DependencyInjection\Security\Factory;
-    
+
     use App\Security\Authentication\Provider\WsseProvider;
 
     class WsseFactory implements SecurityFactoryInterface
@@ -607,7 +607,7 @@ set to any desirable value per firewall.
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/firewall_restriction.rst b/security/firewall_restriction.rst
index 0ce0c2e3ff5..e2cc7037cd9 100644
--- a/security/firewall_restriction.rst
+++ b/security/firewall_restriction.rst
@@ -44,7 +44,7 @@ if the request path matches the configured ``pattern``.
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -101,7 +101,7 @@ only initialize if the host from the request matches against the configuration.
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -159,7 +159,7 @@ the provided HTTP methods.
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -215,7 +215,7 @@ If the above options don't fit your needs you can configure any service implemen
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/force_https.rst b/security/force_https.rst
index 797446ce4b9..f7ee271648a 100644
--- a/security/force_https.rst
+++ b/security/force_https.rst
@@ -31,7 +31,7 @@ access control:
         .. code-block:: xml
 
             <!-- config/packages/security.xml -->
-            <?xml version="1.0" encoding="UTF-8"?>
+            <?xml version="1.0" encoding="UTF-8" ?>
             <srv:container xmlns="http://symfony.com/schema/dic/security"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/form_login.rst b/security/form_login.rst
index 374e21a78b7..6cc958fc9eb 100644
--- a/security/form_login.rst
+++ b/security/form_login.rst
@@ -36,7 +36,7 @@ First, enable ``form_login`` under your firewall:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:srv="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
@@ -431,7 +431,7 @@ a relative/absolute URL or a Symfony route name:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -488,7 +488,7 @@ previously requested URL and always redirect to the default page:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -576,7 +576,7 @@ parameter is included in the request, you may use the value of the
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -642,7 +642,7 @@ option to define a new target via a relative/absolute URL or a Symfony route nam
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -717,7 +717,7 @@ redirects can be customized using the  ``target_path_parameter`` and
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/form_login_setup.rst b/security/form_login_setup.rst
index d78a415ff34..3bce28359a0 100644
--- a/security/form_login_setup.rst
+++ b/security/form_login_setup.rst
@@ -420,7 +420,7 @@ domain:
     .. code-block:: xml
 
         <!-- translations/security.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
diff --git a/security/guard_authentication.rst b/security/guard_authentication.rst
index 7f0ff8b7f0b..de4285a653a 100644
--- a/security/guard_authentication.rst
+++ b/security/guard_authentication.rst
@@ -72,7 +72,7 @@ Next, configure your "user provider" to use this new ``apiToken`` property:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -258,7 +258,7 @@ Finally, configure your ``firewalls`` key in ``security.yaml`` to use this authe
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -458,7 +458,7 @@ completes registration. To do that, use your authenticator and a service called
 
     // src/Controller/RegistrationController.php
     namespace App\Controller;
-    
+
     // ...
     use App\Security\LoginFormAuthenticator;
     use Symfony\Component\HttpFoundation\Request;
diff --git a/security/impersonating_user.rst b/security/impersonating_user.rst
index ca4c1e3947f..d7c1692ba80 100644
--- a/security/impersonating_user.rst
+++ b/security/impersonating_user.rst
@@ -33,7 +33,7 @@ listener:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -167,7 +167,7 @@ also adjust the query parameter name via the ``parameter`` setting:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -224,7 +224,7 @@ be called):
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/json_login_setup.rst b/security/json_login_setup.rst
index a4be5dac0e7..d61b82287bc 100644
--- a/security/json_login_setup.rst
+++ b/security/json_login_setup.rst
@@ -24,7 +24,7 @@ First, enable the JSON login under your firewall:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:srv="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
@@ -173,7 +173,7 @@ The security configuration should be:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:srv="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
diff --git a/security/ldap.rst b/security/ldap.rst
index 3b5b549e7ec..eb4872dfbdf 100644
--- a/security/ldap.rst
+++ b/security/ldap.rst
@@ -160,7 +160,7 @@ use the ``ldap`` user provider.
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -384,7 +384,7 @@ Configuration example for form login
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -437,7 +437,7 @@ Configuration example for HTTP Basic
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -497,7 +497,7 @@ Configuration example for form login and query_string
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/multiple_guard_authenticators.rst b/security/multiple_guard_authenticators.rst
index f9145e1d897..0a93eae6e9c 100644
--- a/security/multiple_guard_authenticators.rst
+++ b/security/multiple_guard_authenticators.rst
@@ -37,7 +37,7 @@ This is how your security configuration can look in action:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -115,7 +115,7 @@ the solution is to split the configuration into two separate firewalls:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/named_encoders.rst b/security/named_encoders.rst
index 22bc333dec4..7c1ca4a068f 100644
--- a/security/named_encoders.rst
+++ b/security/named_encoders.rst
@@ -22,7 +22,7 @@ to apply to all instances of a specific class:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/password_migration.rst b/security/password_migration.rst
index bb77a0504ab..426a9626cbc 100644
--- a/security/password_migration.rst
+++ b/security/password_migration.rst
@@ -49,7 +49,7 @@ on the new encoder to point to the old, legacy encoder(s):
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:security="http://symfony.com/schema/dic/security"
diff --git a/security/user_checkers.rst b/security/user_checkers.rst
index d5374e44b03..068816440ce 100644
--- a/security/user_checkers.rst
+++ b/security/user_checkers.rst
@@ -81,7 +81,7 @@ is the service id of your user checker:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/security/user_provider.rst b/security/user_provider.rst
index 07227868afe..dfebcb449a7 100644
--- a/security/user_provider.rst
+++ b/security/user_provider.rst
@@ -62,7 +62,7 @@ to retrieve them:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -138,7 +138,7 @@ interface only requires one method: ``loadUserByUsername($username)``::
         public function loadUserByUsername($usernameOrEmail)
         {
             $entityManager = $this->getEntityManager();
-            
+
             return $entityManager->createQuery(
                     'SELECT u
                     FROM App\Entity\User u
@@ -169,7 +169,7 @@ To finish this, remove the ``property`` key from the user provider in
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -234,7 +234,7 @@ users will encode their passwords:
     .. code-block:: xml
 
         <!-- config/packages/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
@@ -413,7 +413,7 @@ command will generate a nice skeleton to get you started::
         {
             return User::class === $class || is_subclass_of($class, User::class);
         }
-        
+
         /**
          * Upgrades the encoded password of a user, typically for using a better hash algorithm.
          */
diff --git a/serializer.rst b/serializer.rst
index d416f8fb40a..3518be26607 100644
--- a/serializer.rst
+++ b/serializer.rst
@@ -116,7 +116,7 @@ properties and setters (``setXxx()``) to change properties:
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://symfony.com/schema/dic/services
diff --git a/service_container/tags.rst b/service_container/tags.rst
index 76d4cb9792e..e860c9e7d15 100644
--- a/service_container/tags.rst
+++ b/service_container/tags.rst
@@ -89,7 +89,7 @@ If you want to apply tags automatically for your own services, use the
     .. code-block:: xml
 
         <!-- config/services.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <container xmlns="http://symfony.com/schema/dic/services" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://symfony.com/schema/dic/services https://symfony.com/schema/dic/services/services-1.0.xsd">
             <services>
                 <!-- this config only applies to the services created by this file -->
diff --git a/testing/bootstrap.rst b/testing/bootstrap.rst
index cf1b63621a2..cf6cb97b651 100644
--- a/testing/bootstrap.rst
+++ b/testing/bootstrap.rst
@@ -26,7 +26,7 @@ before running the tests:
 .. code-block:: xml
 
     <!-- phpunit.xml.dist -->
-    <?xml version="1.0" encoding="UTF-8"?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <phpunit
         bootstrap="tests/bootstrap.php"
     >
@@ -39,7 +39,7 @@ cache to be cleared:
 .. code-block:: xml
 
     <!-- phpunit.xml.dist -->
-    <?xml version="1.0" encoding="UTF-8"?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <phpunit>
         <!-- ... -->
 
diff --git a/testing/http_authentication.rst b/testing/http_authentication.rst
index 336f6f12b39..ff32b875a31 100644
--- a/testing/http_authentication.rst
+++ b/testing/http_authentication.rst
@@ -36,7 +36,7 @@ encoders configuration to generate password hashes as fast as possible:
     .. code-block:: xml
 
         <!-- config/packages/test/security.xml -->
-        <?xml version="1.0" encoding="UTF-8"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <srv:container xmlns="http://symfony.com/schema/dic/security"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns:srv="http://symfony.com/schema/dic/services"
diff --git a/translation.rst b/translation.rst
index ac14dd8c318..db096351c7e 100644
--- a/translation.rst
+++ b/translation.rst
@@ -141,7 +141,7 @@ different formats:
     .. code-block:: xml
 
         <!-- translations/messages.fr.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
diff --git a/translation/debug.rst b/translation/debug.rst
index afe1c778e77..bca8702f9a9 100644
--- a/translation/debug.rst
+++ b/translation/debug.rst
@@ -39,7 +39,7 @@ you've already setup some translations for the ``fr`` locale:
     .. code-block:: xml
 
         <!-- translations/messages.fr.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
@@ -70,7 +70,7 @@ and for the ``en`` locale:
     .. code-block:: xml
 
         <!-- translations/messages.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
diff --git a/translation/message_format.rst b/translation/message_format.rst
index 4e637a4335e..eff82a0e123 100644
--- a/translation/message_format.rst
+++ b/translation/message_format.rst
@@ -51,7 +51,7 @@ The basic usage of the MessageFormat allows you to use placeholders (called
     .. code-block:: xml
 
         <!-- translations/messages+intl-icu.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
@@ -112,7 +112,7 @@ typical usage of this is gender:
     .. code-block:: xml
 
         <!-- translations/messages+intl-icu.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
@@ -199,7 +199,7 @@ handle pluralization in your messages (e.g. ``There are 3 apples`` vs
     .. code-block:: xml
 
         <!-- translations/messages+intl-icu.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
@@ -327,7 +327,7 @@ Similar to ``plural``, ``selectordinal`` allows you to use numbers as ordinal sc
     .. code-block:: xml
 
         <!-- translations/messages+intl-icu.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
@@ -391,7 +391,7 @@ using the :phpclass:`IntlDateFormatter`:
     .. code-block:: xml
 
         <!-- translations/messages+intl-icu.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
@@ -433,7 +433,7 @@ The ``number`` formatter allows you to format numbers using Intl's :phpclass:`Nu
     .. code-block:: xml
 
         <!-- translations/messages+intl-icu.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>
diff --git a/translation/xliff.rst b/translation/xliff.rst
index a3c3daab43e..d5fb90e3586 100644
--- a/translation/xliff.rst
+++ b/translation/xliff.rst
@@ -19,7 +19,7 @@ loaded/dumped inside a Symfony application:
 
 .. code-block:: xml
 
-    <?xml version="1.0" encoding="UTF-8"?>
+    <?xml version="1.0" encoding="UTF-8" ?>
     <xliff xmlns="urn:oasis:names:tc:xliff:document:2.1" version="2.1"
         srcLang="fr-FR" trgLang="en-US">
         <file id="messages.en_US">
diff --git a/validation/translations.rst b/validation/translations.rst
index 16df7921327..396d4fd6eaa 100644
--- a/validation/translations.rst
+++ b/validation/translations.rst
@@ -101,7 +101,7 @@ Now, create a ``validators`` catalog file in the ``translations/`` directory:
     .. code-block:: xml
 
         <!-- translations/validators/validators.en.xlf -->
-        <?xml version="1.0"?>
+        <?xml version="1.0" encoding="UTF-8" ?>
         <xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">
             <file source-language="en" datatype="plaintext" original="file.ext">
                 <body>