diff --git a/src/Manager/ForgotPasswordManager.php b/src/Manager/ForgotPasswordManager.php
index 4a70c1e..f5dd60e 100644
--- a/src/Manager/ForgotPasswordManager.php
+++ b/src/Manager/ForgotPasswordManager.php
@@ -43,7 +43,7 @@ public function __construct(
         $this->providerChain = $providerChain;
     }
 
-    public function resetPassword($propertyName, $value, ProviderInterface $provider = null): void
+    public function resetPassword($propertyName, $value, ?ProviderInterface $provider = null): void
     {
         /* @var null|Provider $provider */
         if (!$provider) {
@@ -88,7 +88,7 @@ public function resetPassword($propertyName, $value, ProviderInterface $provider
      *
      * @return bool
      */
-    public function updatePassword(AbstractPasswordToken $passwordToken, $password, ProviderInterface $provider = null)
+    public function updatePassword(AbstractPasswordToken $passwordToken, $password, ?ProviderInterface $provider = null)
     {
         /* @var null|Provider $provider */
         if (!$provider) {
diff --git a/src/Manager/PasswordTokenManager.php b/src/Manager/PasswordTokenManager.php
index a673ea0..8e23293 100644
--- a/src/Manager/PasswordTokenManager.php
+++ b/src/Manager/PasswordTokenManager.php
@@ -35,7 +35,7 @@ public function __construct(ProviderChainInterface $providerChain)
     /**
      * @return AbstractPasswordToken
      */
-    public function createPasswordToken($user, \DateTime $expiresAt = null, ProviderInterface $provider = null)
+    public function createPasswordToken($user, ?\DateTime $expiresAt = null, ?ProviderInterface $provider = null)
     {
         /* @var Provider $provider */
         if (!$provider) {
@@ -76,7 +76,7 @@ public function createPasswordToken($user, \DateTime $expiresAt = null, Provider
      *
      * @return AbstractPasswordToken
      */
-    public function findOneByToken($token, ProviderInterface $provider = null)
+    public function findOneByToken($token, ?ProviderInterface $provider = null)
     {
         /* @var null|Provider $provider */
         if (!$provider) {
@@ -90,7 +90,7 @@ public function findOneByToken($token, ProviderInterface $provider = null)
     /**
      * @return AbstractPasswordToken
      */
-    public function findOneByUser($user, ProviderInterface $provider = null)
+    public function findOneByUser($user, ?ProviderInterface $provider = null)
     {
         /* @var null|Provider $provider */
         if (!$provider) {
diff --git a/src/Provider/ProviderChain.php b/src/Provider/ProviderChain.php
index 20f7a5d..3a11d61 100644
--- a/src/Provider/ProviderChain.php
+++ b/src/Provider/ProviderChain.php
@@ -30,7 +30,7 @@ public function __construct(iterable $providers)
     /**
      * Returns a provider by its name, without name the default provider is returned.
      */
-    public function get(string $name = null): ProviderInterface
+    public function get(?string $name = null): ProviderInterface
     {
         if (null === $name) {
             return $this->getDefault();
diff --git a/src/Provider/ProviderChainInterface.php b/src/Provider/ProviderChainInterface.php
index 12ea3b1..d0ce5aa 100644
--- a/src/Provider/ProviderChainInterface.php
+++ b/src/Provider/ProviderChainInterface.php
@@ -15,7 +15,7 @@
 
 interface ProviderChainInterface
 {
-    public function get(string $name = null): ProviderInterface;
+    public function get(?string $name = null): ProviderInterface;
 
     /**
      * @return array<string, ProviderInterface>