symfony · nicolas-grekas · Dec 19, 2025 · Dec 16, 2025
diff --git a/UPGRADE-8.1.md b/UPGRADE-8.1.md
@@ -6,6 +6,11 @@ DependencyInjection
 
  * Deprecate configuring options `alias`, `parent`, `synthetic`, `file`, `arguments`, `properties`, `configurator` or `calls` when using `from_callable`
 
+DoctrineBridge
+--------------
+
+ * Deprecate setting an `$aliasMap` in `RegisterMappingsPass`. Namespace aliases are no longer supported in Doctrine.
+
 FrameworkBundle
 ---------------
 

diff --git a/src/Symfony/Bridge/Doctrine/CHANGELOG.md b/src/Symfony/Bridge/Doctrine/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+8.1
+---
+
+ * Deprecate setting an `$aliasMap` in `RegisterMappingsPass`. Namespace aliases are no longer supported in Doctrine.
+
 8.0
 ---
 

diff --git a/src/Symfony/Bridge/Doctrine/DependencyInjection/CompilerPass/RegisterMappingsPass.php b/src/Symfony/Bridge/Doctrine/DependencyInjection/CompilerPass/RegisterMappingsPass.php
@@ -65,8 +65,12 @@ public function __construct(
         private readonly string $registerAliasMethodName = '',
         private readonly array $aliasMap = [],
     ) {
-        if ($aliasMap && (!$configurationPattern || !$registerAliasMethodName)) {
-            throw new \InvalidArgumentException('configurationPattern and registerAliasMethodName are required to register namespace alias.');
+        if ($aliasMap) {
+            trigger_deprecation('symfony/doctrine-bridge', '8.1', 'The property RegisterMappingsPass::$aliasMap is deprecated and will be removed in 9.0. Namespace alias are no longer supported.');
+
+            if (!$configurationPattern || !$registerAliasMethodName) {
+                throw new \InvalidArgumentException('configurationPattern and registerAliasMethodName are required to register namespace alias.');
+            }
         }
     }
 
@@ -103,7 +107,7 @@ public function process(ContainerBuilder $container): void
      * Get the service name of the metadata chain driver that the mappings
      * should be registered with.
      *
-     * @throws InvalidArgumentException if non of the managerParameters has a
+     * @throws InvalidArgumentException if none of the managerParameters has a
      *                                  non-empty value
      */
     protected function getChainDriverServiceName(ContainerBuilder $container): string

diff --git a/src/Symfony/Bridge/Doctrine/composer.json b/src/Symfony/Bridge/Doctrine/composer.json
@@ -19,6 +19,7 @@
         "php": ">=8.4",
         "doctrine/event-manager": "^2",
         "doctrine/persistence": "^3.1|^4",
+        "symfony/deprecation-contracts": "^2.5|^3",
         "symfony/polyfill-ctype": "^1.8",
         "symfony/polyfill-mbstring": "^1.0",
         "symfony/service-contracts": "^2.5|^3"