diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d2549cc..4a440e8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,8 +14,9 @@ jobs:
           - 8.1
           - 8.2
           - 8.3
+          - 8.4
         include:
-          - php: 8.4
+          - php: 8.5
             prefer: stable
             experimental: true
         prefer:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 29cf776..d4d8c25 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,14 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Fixed
+- Implicitly marking parameters as nullable is deprecated, the explicit nullable type must be used instead
+
+### Added
+- Loggers map callable members
+- PHP 8.4 mainline support
+- PHP 8.5 experimental support
+
 ## [4.0.1] - 2024-10-09
 
 ### Fixed
diff --git a/Dockerfile b/Dockerfile
index 8c62c34..6b32a2b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM php:8.0-cli
+FROM php:8.4-cli
 
 RUN apt-get update \
     && apt-get install -y \
diff --git a/README.md b/README.md
index 91a7d24..d60cc07 100644
--- a/README.md
+++ b/README.md
@@ -65,9 +65,9 @@ return [
     ],
     'loggers' => [
        // For suitable logger injections use map, where keys are your services, that implement LoggerAwareInterface
-       // and value is logger instances
+       // and value is logger instances or callable with logic for instantiate it. 
        LoggerAwareClass::class        => $logger,
-       AnotherLoggerAwareClass::class => $anotherLogger,
+       AnotherLoggerAwareClass::class => fn(\Psr\Container\ContainerInterface $container) => new \Psr\Log\NullLogger(),
     ],   
 ];
 ```
diff --git a/composer.json b/composer.json
index 2beb8ac..e0178bd 100644
--- a/composer.json
+++ b/composer.json
@@ -9,7 +9,7 @@
         }
     },
     "require-dev": {
-        "phpunit/phpunit": "^9.3"
+        "phpunit/phpunit": "^9.6"
     },
     "license": "BSD-2-Clause",
     "authors": [
diff --git a/src/Injector.php b/src/Injector.php
index 9d1c113..e49e4e7 100644
--- a/src/Injector.php
+++ b/src/Injector.php
@@ -29,7 +29,7 @@ class Injector implements ContainerInterface
 
     private array $loggersMap = [];
 
-    public function __construct(LoggerInterface $logger = null)
+    public function __construct(?LoggerInterface $logger = null)
     {
         $this->loggerHelper = new LoggerHelper($logger ?: new NullLogger());
     }
@@ -87,6 +87,9 @@ public function createInstance($class): object
         if ($this->isLoggerInjectionRequired($instance)) {
             if(array_key_exists($class, $this->loggersMap)) {
                 $logger = $this->loggersMap[$class];
+                if(!$logger instanceof LoggerInterface && is_callable($logger)) {
+                    $logger = $logger($this);
+                }
             } else {
                 $logger = $this->getService(LoggerInterface::class);
             }
@@ -97,7 +100,7 @@ public function createInstance($class): object
         return $instance;
     }
 
-    public function registerService($implementation, string $interface = null): void
+    public function registerService($implementation, ?string $interface = null): void
     {
         $interface = $interface ?: $implementation;
         if (isset($this->serviceMap[$interface])) {
diff --git a/tests/Fixture/ClassWithNullableConstructorArgs.php b/tests/Fixture/ClassWithNullableConstructorArgs.php
index 93becc9..b4b4f71 100644
--- a/tests/Fixture/ClassWithNullableConstructorArgs.php
+++ b/tests/Fixture/ClassWithNullableConstructorArgs.php
@@ -14,7 +14,7 @@ class ClassWithNullableConstructorArgs
      */
     private $anotherService;
 
-    public function __construct(AnotherServiceInterface $anotherService = null)
+    public function __construct(?AnotherServiceInterface $anotherService = null)
     {
         $this->anotherService = $anotherService ?: new DefaultAnotherServiceImpl();
     }
@@ -28,4 +28,4 @@ public function getAnotherService(): AnotherServiceInterface
 class DefaultAnotherServiceImpl implements AnotherServiceInterface
 {
 
-}
\ No newline at end of file
+}
diff --git a/tests/Fixture/ClassWithTypedScalarConstructorArgDefaultValue.php b/tests/Fixture/ClassWithTypedScalarConstructorArgDefaultValue.php
index e4ffd16..0499081 100644
--- a/tests/Fixture/ClassWithTypedScalarConstructorArgDefaultValue.php
+++ b/tests/Fixture/ClassWithTypedScalarConstructorArgDefaultValue.php
@@ -22,7 +22,7 @@ class ClassWithTypedScalarConstructorArgDefaultValue
      */
     private $notTypedArg;
 
-    public function __construct(int $value = self::DEFAULT_VALUE, array $array = null, $notTypedArg = null)
+    public function __construct(int $value = self::DEFAULT_VALUE, ?array $array = null, $notTypedArg = null)
     {
         $this->value = $value;
         $this->array = $array;
@@ -33,4 +33,4 @@ public function getValue()
     {
         return $this->value;
     }
-}
\ No newline at end of file
+}
diff --git a/tests/InjectorTest.php b/tests/InjectorTest.php
index 34c19df..60ed8b8 100644
--- a/tests/InjectorTest.php
+++ b/tests/InjectorTest.php
@@ -232,13 +232,14 @@ public function testLoggerMap()
     {
         $logger = new NullLogger();
         $anotherLogger = new NullLogger();
+        $anotherLoggerCallable = fn() => $anotherLogger;
 
         $injector = new Injector();
         $injector->allowInstantiateNotRegisteredTypes(true);
         $injector->enableLoggerAwareInjection();
         $injector->setLoggersMap([
             LoggerAwareClass::class        => $logger,
-            AnotherLoggerAwareClass::class => $anotherLogger,
+            AnotherLoggerAwareClass::class => $anotherLoggerCallable,
         ]);
 
         /** @var LoggerAwareClass $loggerAwareInstance */