diff --git a/composer.json b/composer.json
index 7de07557..1fe57fb4 100644
--- a/composer.json
+++ b/composer.json
@@ -78,6 +78,8 @@
         "friendsofphp/php-cs-fixer": "*",
         "phpstan/extension-installer": "*",
         "phpstan/phpstan": "*",
+        "phpstan/phpstan-deprecation-rules": "*",
+        "phpstan/phpstan-phpunit": "*",
         "phpstan/phpstan-symfony": "*",
         "phpunit/phpunit": "^10.5|^11|^12|^13",
         "rector/rector": "*",
diff --git a/phpstan.neon b/phpstan.neon
index 1c22ba10..84f792d9 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -5,3 +5,24 @@ parameters:
         - tests
     inferPrivatePropertyTypeFromConstructor: true
     treatPhpDocTypesAsCertain: false
+    # Same ignores in all the process bundles: not all of them match in each bundle
+    reportUnmatchedIgnoredErrors: false
+    ignoreErrors:
+        # PHPUnit 13 deprecates expectExceptionMessage() (sebastianbergmann/phpunit#6560), still needed with PHPUnit 11 and 12
+        - message: '#^Call to deprecated method expectExceptionMessage\(\) of class PHPUnit\\Framework\\TestCase#'
+          path: tests/*
+        # Symfony 8.1 deprecates HttpKernel\Bundle\BundleInterface: its replacement does not exist in Symfony 6.4 and 7.4
+        - message: '#typehint with deprecated interface Symfony\\Component\\HttpKernel\\Bundle\\BundleInterface#'
+          path: tests/*
+        # The tests of the deprecated code of the bundles use it
+        - message: '#deprecated .*CleverAge\\#'
+          path: tests/*
+        # Assertions on values already known by PHPStan, kept as regression checks (or values changed by reference)
+        - identifier: staticMethod.alreadyNarrowedType
+          path: tests/*
+        - identifier: method.alreadyNarrowedType
+          path: tests/*
+        - identifier: staticMethod.impossibleType
+          path: tests/*
+        - identifier: method.impossibleType
+          path: tests/*
diff --git a/src/Command/ProcessHelpCommand.php b/src/Command/ProcessHelpCommand.php
index af865943..4fc0e827 100644
--- a/src/Command/ProcessHelpCommand.php
+++ b/src/Command/ProcessHelpCommand.php
@@ -85,6 +85,7 @@ public function __construct(
                 TaskRegistry::class,
                 TaskRegistry::class,
             );
+            // @phpstan-ignore property.deprecated (kept for BC until v6.0)
             $this->container = $taskRegistry;
             // Same behaviour as before the task registry: any service of the container
             $taskRegistry = new TaskRegistry($taskRegistry, $taskRegistry);
diff --git a/src/Configuration/TaskConfiguration.php b/src/Configuration/TaskConfiguration.php
index 9dd6890a..e6031d8d 100644
--- a/src/Configuration/TaskConfiguration.php
+++ b/src/Configuration/TaskConfiguration.php
@@ -70,6 +70,7 @@ public function __construct(
         protected string $errorStrategy = self::STRATEGY_SKIP,
         protected string $logLevel = LogLevel::CRITICAL,
     ) {
+        // @phpstan-ignore property.deprecated (kept for BC until v6.0)
         $this->logErrors = LogLevel::DEBUG !== $logLevel;
     }
 
diff --git a/src/DependencyInjection/Compiler/UnavailableServicesCompilerPass.php b/src/DependencyInjection/Compiler/UnavailableServicesCompilerPass.php
index af76a019..f991d8d4 100644
--- a/src/DependencyInjection/Compiler/UnavailableServicesCompilerPass.php
+++ b/src/DependencyInjection/Compiler/UnavailableServicesCompilerPass.php
@@ -107,6 +107,7 @@ private function replace(ContainerBuilder $container, string $message, array $cl
                 // The code is needed by the transformer registry: the one of the tag (see TransformerLocatorCompilerPass),
                 // or, for a definition tagged without code (deprecated), the one returned by the bundle transformer
                 $code = $this->getTagCode($original)
+                    // @phpstan-ignore method.deprecated (transformer registered without code, until v6.0)
                     ?? (new \ReflectionClass($class))->newInstanceWithoutConstructor()->getCode();
                 $definition = new Definition(UnavailableTransformer::class, [$code, $text]);
             } else {
diff --git a/src/Model/SubprocessInstance.php b/src/Model/SubprocessInstance.php
index 274b9f4e..e192d587 100644
--- a/src/Model/SubprocessInstance.php
+++ b/src/Model/SubprocessInstance.php
@@ -71,6 +71,7 @@ public function __construct(
                 self::class,
             );
             $this->environment ??= $consolePath->getEnvironment();
+            // @phpstan-ignore property.deprecated (kept for BC until v6.0)
             $this->logDir = $consolePath->getLogDir().'/process';
             $consolePath = $consolePath->getProjectDir().'/bin/console';
         }
diff --git a/src/Registry/TransformerRegistry.php b/src/Registry/TransformerRegistry.php
index 4bbda85b..a21c974b 100644
--- a/src/Registry/TransformerRegistry.php
+++ b/src/Registry/TransformerRegistry.php
@@ -91,7 +91,9 @@ public function getTransformer(string $code): TransformerInterface
         if (!$transformer instanceof TransformerInterface) {
             throw new UnexpectedValueException(\sprintf('The service of the transformer "%s" must implement "%s".', $code, TransformerInterface::class));
         }
+        // @phpstan-ignore method.deprecated (the code returned by getCode() must stay the same until v6.0)
         if ($code !== $transformer->getCode()) {
+            // @phpstan-ignore method.deprecated (the code returned by getCode() must stay the same until v6.0)
             throw new UnexpectedValueException(\sprintf('The transformer "%s" is registered with the code "%s" but its getCode() method returns "%s": both must be the same.', $transformer::class, $code, $transformer->getCode()));
         }
 
diff --git a/src/Task/Process/CommandRunnerTask.php b/src/Task/Process/CommandRunnerTask.php
index da324256..0b87d84e 100644
--- a/src/Task/Process/CommandRunnerTask.php
+++ b/src/Task/Process/CommandRunnerTask.php
@@ -47,6 +47,7 @@ public function __construct(KernelInterface|string $projectDir)
                 KernelInterface::class,
                 self::class,
             );
+            // @phpstan-ignore property.deprecated (kept for BC until v6.0)
             $this->kernel = $projectDir;
             $projectDir = $projectDir->getProjectDir();
         }
diff --git a/src/Task/Process/ProcessLauncherTask.php b/src/Task/Process/ProcessLauncherTask.php
index 2d8a079f..65af78ee 100644
--- a/src/Task/Process/ProcessLauncherTask.php
+++ b/src/Task/Process/ProcessLauncherTask.php
@@ -74,6 +74,7 @@ public function __construct(
                 KernelInterface::class,
                 self::class,
             );
+            // @phpstan-ignore property.deprecated (kept for BC until v6.0)
             $this->kernel = $consolePath;
             $this->environment ??= $consolePath->getEnvironment();
             $consolePath = $consolePath->getProjectDir().'/bin/console';