diff --git a/Authentication/AuthenticationProviderManager.php b/Authentication/AuthenticationProviderManager.php
index 0c0a2062..a0c95ab8 100644
--- a/Authentication/AuthenticationProviderManager.php
+++ b/Authentication/AuthenticationProviderManager.php
@@ -65,7 +65,7 @@ public function authenticate(TokenInterface $token)
 
         foreach ($this->providers as $provider) {
             if (!$provider instanceof AuthenticationProviderInterface) {
-                throw new \InvalidArgumentException(sprintf('Provider "%s" must implement the AuthenticationProviderInterface.', \get_class($provider)));
+                throw new \InvalidArgumentException(sprintf('Provider "%s" must implement the AuthenticationProviderInterface.', get_debug_type($provider)));
             }
 
             if (!$provider->supports($token)) {
diff --git a/Authentication/Provider/RememberMeAuthenticationProvider.php b/Authentication/Provider/RememberMeAuthenticationProvider.php
index 670390e4..9a688adc 100644
--- a/Authentication/Provider/RememberMeAuthenticationProvider.php
+++ b/Authentication/Provider/RememberMeAuthenticationProvider.php
@@ -52,7 +52,7 @@ public function authenticate(TokenInterface $token)
         $user = $token->getUser();
 
         if (!$token->getUser() instanceof UserInterface) {
-            throw new LogicException(sprintf('Method "%s::getUser()" must return a "%s" instance, "%s" returned.', \get_class($token), UserInterface::class, \is_object($user) ? \get_class($user) : \gettype($user)));
+            throw new LogicException(sprintf('Method "%s::getUser()" must return a "%s" instance, "%s" returned.', get_debug_type($token), UserInterface::class, get_debug_type($user)));
         }
 
         $this->userChecker->checkPreAuth($user);
diff --git a/Encoder/EncoderFactory.php b/Encoder/EncoderFactory.php
index cad50180..06bc591e 100644
--- a/Encoder/EncoderFactory.php
+++ b/Encoder/EncoderFactory.php
@@ -50,7 +50,7 @@ public function getEncoder($user)
         }
 
         if (null === $encoderKey) {
-            throw new \RuntimeException(sprintf('No encoder has been configured for account "%s".', \is_object($user) ? \get_class($user) : $user));
+            throw new \RuntimeException(sprintf('No encoder has been configured for account "%s".', \is_object($user) ? get_debug_type($user) : $user));
         }
 
         if (!$this->encoders[$encoderKey] instanceof PasswordEncoderInterface) {
diff --git a/User/ChainUserProvider.php b/User/ChainUserProvider.php
index af5a0ebb..23321250 100644
--- a/User/ChainUserProvider.php
+++ b/User/ChainUserProvider.php
@@ -91,7 +91,7 @@ public function refreshUser(UserInterface $user)
             $e->setUsername($user->getUsername());
             throw $e;
         } else {
-            throw new UnsupportedUserException(sprintf('There is no user provider for user "%s". Shouldn\'t the "supportsClass()" method of your user provider return true for this classname?', \get_class($user)));
+            throw new UnsupportedUserException(sprintf('There is no user provider for user "%s". Shouldn\'t the "supportsClass()" method of your user provider return true for this classname?', get_debug_type($user)));
         }
     }
 
diff --git a/User/InMemoryUserProvider.php b/User/InMemoryUserProvider.php
index 71bdec54..8d084cd5 100644
--- a/User/InMemoryUserProvider.php
+++ b/User/InMemoryUserProvider.php
@@ -74,7 +74,7 @@ public function loadUserByUsername(string $username)
     public function refreshUser(UserInterface $user)
     {
         if (!$user instanceof User) {
-            throw new UnsupportedUserException(sprintf('Instances of "%s" are not supported.', \get_class($user)));
+            throw new UnsupportedUserException(sprintf('Instances of "%s" are not supported.', get_debug_type($user)));
         }
 
         $storedUser = $this->getUser($user->getUsername());
diff --git a/composer.json b/composer.json
index c8bfb07d..fc500b28 100644
--- a/composer.json
+++ b/composer.json
@@ -18,6 +18,7 @@
     "require": {
         "php": "^7.2.5",
         "symfony/event-dispatcher-contracts": "^1.1|^2",
+        "symfony/polyfill-php80": "^1.15",
         "symfony/service-contracts": "^1.1.6|^2",
         "symfony/deprecation-contracts": "^2.1"
     },