diff --git a/.gitignore b/.gitignore
index 01d169a..9ab55da 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 vendor/
 composer.lock
+/*.rdb
 
 ###> squizlabs/php_codesniffer ###
 /.phpcs-cache
diff --git a/DependencyInjection/RedisExtension.php b/DependencyInjection/RedisExtension.php
index 1a5b403..b4ff4e4 100644
--- a/DependencyInjection/RedisExtension.php
+++ b/DependencyInjection/RedisExtension.php
@@ -13,7 +13,7 @@ class RedisExtension extends ConfigurableExtension
     /**
      * loadInternal.
      *
-     * @param mixed[]          $configs
+     * @param array{clients: array<string, array<mixed>>} $configs
      * @param ContainerBuilder $container
      */
     protected function loadInternal(array $configs, ContainerBuilder $container): void
diff --git a/Redis/Client.php b/Redis/Client.php
index db9bab9..cea1f89 100644
--- a/Redis/Client.php
+++ b/Redis/Client.php
@@ -21,7 +21,9 @@ public function __construct($parameters = null, $options = null)
      */
     public function pop(string $key): ?string
     {
-        return $this->call('lpop', [$key]);
+        $result = $this->call('lpop', [$key]);
+
+        return null === $result ? null : (string) $result;
     }
 
     /**
@@ -29,7 +31,7 @@ public function pop(string $key): ?string
      */
     public function push(string $key, ...$values): int
     {
-        return $this->call('rpush', array_merge([$key], $values));
+        return (int) $this->call('rpush', array_merge([$key], $values));
     }
 
     /**
@@ -37,7 +39,7 @@ public function push(string $key, ...$values): int
      */
     public function count(string $key): int
     {
-        return $this->call('llen', [$key]);
+        return (int) $this->call('llen', [$key]);
     }
 
     /**
@@ -45,7 +47,7 @@ public function count(string $key): int
      */
     public function remove(string $key): int
     {
-        return $this->call('del', [$key]);
+        return (int) $this->call('del', [$key]);
     }
 
     /**
@@ -54,10 +56,13 @@ public function remove(string $key): int
      * @param string  $command   the command ID
      * @param mixed[] $arguments the arguments for the command
      *
-     * @return mixed
+     * @return int|bool|string|float|null
      */
     protected function call(string $command, array $arguments = [])
     {
-        return $this->executeCommand($this->createCommand($command, $arguments));
+        /** @var int|bool|string|float|null $result */
+        $result = $this->executeCommand($this->createCommand($command, $arguments));
+
+        return $result;
     }
 }
diff --git a/Tests/Fixtures/app/AppKernel.php b/Tests/Fixtures/app/AppKernel.php
index b3e393c..c1e32e9 100644
--- a/Tests/Fixtures/app/AppKernel.php
+++ b/Tests/Fixtures/app/AppKernel.php
@@ -45,6 +45,7 @@ public function getLogDir(): string
 
     public function registerContainerConfiguration(LoaderInterface $loader): void
     {
+        // @phpstan-ignore-next-line
         if (Kernel::VERSION_ID < 53000) {
             $loader->load($this->getRootDir() . '/config/config_test.yml');
 
diff --git a/Tests/Redis/ClientTest.php b/Tests/Redis/ClientTest.php
index 5e462e4..2a4987d 100644
--- a/Tests/Redis/ClientTest.php
+++ b/Tests/Redis/ClientTest.php
@@ -3,6 +3,7 @@
 namespace SymfonyBundles\RedisBundle\Tests\Redis;
 
 use Exception;
+use Predis\Response\Status;
 use SymfonyBundles\RedisBundle\Tests\TestCase;
 use SymfonyBundles\RedisBundle\Redis\ClientInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
@@ -56,7 +57,9 @@ public function testSingleConnection(): void
             ],
         ]);
 
-        $this->assertSame('OK', $client->flushall()->getPayload());
+        $result = $client->flushall();
+        $this->assertInstanceOf(Status::class, $result);
+        $this->assertSame('OK', $result->getPayload());
     }
 
     /**
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 6901494..eec6b84 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -4,7 +4,3 @@ parameters:
 			message: "#^Call to an undefined method Symfony\\\\Component\\\\Config\\\\Definition\\\\Builder\\\\NodeDefinition\\:\\:children\\(\\)\\.$#"
 			count: 1
 			path: DependencyInjection/Configuration.php
-		-
-			message: '#^Comparison operation "<" between 70103 and 53000 is always false.$#'
-			count: 1
-			path: Tests/Fixtures/app/AppKernel.php
diff --git a/phpstan.neon b/phpstan.neon
index 00ba427..f42a237 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -2,7 +2,7 @@ includes:
     - phpstan-baseline.neon
 
 parameters:
-    level: 8
+    level: max
     paths:
         - DependencyInjection/
         - Redis/