diff --git a/src/Symfony/Bridge/PhpUnit/ClassExistsMock.php b/src/Symfony/Bridge/PhpUnit/ClassExistsMock.php
index fbd0a4fa4d..e8ca4ac940 100644
--- a/src/Symfony/Bridge/PhpUnit/ClassExistsMock.php
+++ b/src/Symfony/Bridge/PhpUnit/ClassExistsMock.php
@@ -30,17 +30,17 @@ class ClassExistsMock
 
     public static function class_exists($name, $autoload = true)
     {
-        return (bool) (self::$classes[ltrim($name, '\\')] ?? class_exists($name, $autoload));
+        return (bool) (self::$classes[ltrim($name, '\\')] ?? \class_exists($name, $autoload));
     }
 
     public static function interface_exists($name, $autoload = true)
     {
-        return (bool) (self::$classes[ltrim($name, '\\')] ?? interface_exists($name, $autoload));
+        return (bool) (self::$classes[ltrim($name, '\\')] ?? \interface_exists($name, $autoload));
     }
 
     public static function trait_exists($name, $autoload = true)
     {
-        return (bool) (self::$classes[ltrim($name, '\\')] ?? trait_exists($name, $autoload));
+        return (bool) (self::$classes[ltrim($name, '\\')] ?? \trait_exists($name, $autoload));
     }
 
     public static function register($class)
diff --git a/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php b/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php
index 313f3e94c4..0cdfea718d 100644
--- a/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php
+++ b/src/Symfony/Component/Security/Core/Encoder/SodiumPasswordEncoder.php
@@ -48,11 +48,15 @@ final class SodiumPasswordEncoder implements PasswordEncoderInterface, SelfSalti
 
     public static function isSupported(): bool
     {
+        if (\extension_loaded('libsodium') || \function_exists('sodium_crypto_pwhash_str')) {
+            return true;
+        }
+
         if (class_exists('ParagonIE_Sodium_Compat') && method_exists('ParagonIE_Sodium_Compat', 'crypto_pwhash_is_available')) {
             return \ParagonIE_Sodium_Compat::crypto_pwhash_is_available();
         }
 
-        return \function_exists('sodium_crypto_pwhash_str') || \extension_loaded('libsodium');
+        return false;
     }
 
     /**