diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 897ea0c..c434ac7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php: [ 7.4, 8.0, 8.1, 8.2 ]
+        php: [ 7.4, 8.0, 8.1, 8.2, 8.3, 8.4, 8.5 ]
         redis-version: [4, 5, 6]
     steps:
       - uses: actions/checkout@v2
diff --git a/src/Kdyby/Redis/DI/Config/RedisSchema.php b/src/Kdyby/Redis/DI/Config/RedisSchema.php
index c90d43a..b271642 100644
--- a/src/Kdyby/Redis/DI/Config/RedisSchema.php
+++ b/src/Kdyby/Redis/DI/Config/RedisSchema.php
@@ -40,7 +40,7 @@ public function normalize($value, \Nette\Schema\Context $context)
 			}
 		}
 
-		$value['clients'][NULL] = $client;
+		$value['clients'][''] = $client;
 
 		return $this->getSchema()->normalize($value, $context);
 	}
@@ -94,7 +94,7 @@ private function getSchema(): \Nette\Schema\Schema
 				'clients' => \Nette\Schema\Expect::arrayOf(
 					new \Kdyby\Redis\DI\Config\ClientSchema($this->builder)
 				)->default([
-					NULL => [
+					'' => [
 						'host' => '127.0.0.1',
 						'port' => \Kdyby\Redis\RedisClient::DEFAULT_PORT,
 						'timeout' => 10,
diff --git a/src/Kdyby/Redis/DI/RedisExtension.php b/src/Kdyby/Redis/DI/RedisExtension.php
index c0f1e9e..1c7b599 100644
--- a/src/Kdyby/Redis/DI/RedisExtension.php
+++ b/src/Kdyby/Redis/DI/RedisExtension.php
@@ -86,7 +86,7 @@ protected function buildClient(?string $name, array $config): \Nette\DI\Definiti
 			$client->setAutowired(FALSE);
 		}
 
-		$this->configuredClients[$name] = $config;
+		$this->configuredClients[$name ?: ''] = $config;
 
 		$client->addSetup('setupLockDuration', [$config['lockDuration'], $config['lockAcquireTimeout']]);
 		$client->addSetup('setConnectionAttempts', [$config['connectionAttempts']]);
@@ -163,7 +163,7 @@ protected function loadSession(array $config): void
 
 		$builder = $this->getContainerBuilder();
 
-		$clientConfig = $config['clients'][NULL];
+		$clientConfig = $config['clients'][''];
 
 		$sessionConfig = \Nette\DI\Config\Helpers::merge(\is_array($config['session']) ? $config['session'] : [], [
 			'host' => $clientConfig['host'],