diff --git a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
index dafd4c46bb0fc..c081103a8071e 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
+++ b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
@@ -53,6 +53,8 @@ CHANGELOG
    `EventDispatcherDebugCommand`, `RouterDebugCommand`, `RouterMatchCommand`,
    `TranslationDebugCommand`, `TranslationUpdateCommand`, `XliffLintCommand`
     and `YamlLintCommand` classes have been marked as final
+ * Deprecated the `web_profiler.position` config option (in Symfony 4.0 the toolbar
+   will always be displayed at the bottom).
 
 3.3.0
 -----
diff --git a/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php
index 957a683ca3563..e07b28925de41 100644
--- a/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/WebProfilerBundle/DependencyInjection/Configuration.php
@@ -39,6 +39,7 @@ public function getConfigTreeBuilder()
                 ->booleanNode('toolbar')->defaultFalse()->end()
                 ->scalarNode('position')
                     ->defaultValue('bottom')
+                    ->setDeprecated('The "web_profiler.position" configuration key has been deprecated in Symfony 3.4 and it will be removed in 4.0.')
                     ->validate()
                         ->ifNotInArray(array('bottom', 'top'))
                         ->thenInvalid('The CSS position %s is not supported')