diff --git a/DataStorage/Cache/Connection/CacheValueType.php b/DataStorage/Cache/Connection/CacheValueType.php
index 71b154c7e..e1e622eb0 100755
--- a/DataStorage/Cache/Connection/CacheValueType.php
+++ b/DataStorage/Cache/Connection/CacheValueType.php
@@ -34,7 +34,7 @@ abstract class CacheValueType extends Enum
 
     public const _ARRAY = 2; /* Data is array */
 
-    public const _SERIALIZABLE = 3; /* Data implements \Serializable */
+    public const _SERIALIZABLE = 3; /* Data implements __serialize and __unserialize() */
 
     public const _FLOAT = 4; /* Data is float */
 
diff --git a/DataStorage/Cache/Connection/ConnectionAbstract.php b/DataStorage/Cache/Connection/ConnectionAbstract.php
index 4ba8a59c2..2f75b2aba 100755
--- a/DataStorage/Cache/Connection/ConnectionAbstract.php
+++ b/DataStorage/Cache/Connection/ConnectionAbstract.php
@@ -164,8 +164,6 @@ abstract class ConnectionAbstract implements ConnectionInterface
             return CacheValueType::_ARRAY;
         } elseif ($value === null) {
             return CacheValueType::_NULL;
-        } elseif ($value instanceof \Serializable) {
-            return CacheValueType::_SERIALIZABLE;
         } elseif ($value instanceof \JsonSerializable) {
             return CacheValueType::_JSONSERIALIZABLE;
         }
diff --git a/DataStorage/Cache/Connection/FileCache.php b/DataStorage/Cache/Connection/FileCache.php
index ca72214f9..87c5f8135 100644
--- a/DataStorage/Cache/Connection/FileCache.php
+++ b/DataStorage/Cache/Connection/FileCache.php
@@ -27,7 +27,7 @@ use phpOMS\System\File\Local\File;
  * This implementation uses the hard drive as cache by saving data to the disc as text files.
  * The text files follow a defined strucuture which allows this implementation to parse the cached data.
  *
- * Allowed datatypes: null, int, bool, float, string, \DateTime, \JsonSerializable, \Serializable
+ * Allowed datatypes: null, int, bool, float, string, \DateTime, \JsonSerializable
  * File structure:
  *      data type (1 byte)
  *      delimiter (1 byte)
diff --git a/DataStorage/Cache/Connection/MemCached.php b/DataStorage/Cache/Connection/MemCached.php
index dc0bd4453..17f3e8a70 100644
--- a/DataStorage/Cache/Connection/MemCached.php
+++ b/DataStorage/Cache/Connection/MemCached.php
@@ -94,7 +94,7 @@ final class MemCached extends ConnectionAbstract
             return;
         }
 
-        if (!(\is_scalar($value) || $value === null || \is_array($value) || $value instanceof \JsonSerializable || $value instanceof \Serializable)) {
+        if (!(\is_scalar($value) || $value === null || \is_array($value) || $value instanceof \JsonSerializable) {
             throw new \InvalidArgumentException();
         }
 
@@ -110,7 +110,7 @@ final class MemCached extends ConnectionAbstract
             return false;
         }
 
-        if (!(\is_scalar($value) || $value === null || \is_array($value) || $value instanceof \JsonSerializable || $value instanceof \Serializable)) {
+        if (!(\is_scalar($value) || $value === null || \is_array($value) || $value instanceof \JsonSerializable) {
             throw new \InvalidArgumentException();
         }
 
diff --git a/DataStorage/Database/Query/Builder.php b/DataStorage/Database/Query/Builder.php
index 3f9ebe2bc..d4664f282 100644
--- a/DataStorage/Database/Query/Builder.php
+++ b/DataStorage/Database/Query/Builder.php
@@ -1454,8 +1454,6 @@ class Builder extends BuilderAbstract
             return $column;
         } elseif ($column instanceof Column) {
             return $column->getColumn();
-        } elseif ($column instanceof \Serializable) {
-            return $column->serialize();
         } elseif ($column instanceof self) {
             return \md5($column->toSql());
         }
diff --git a/DataStorage/Database/Query/Grammar/Grammar.php b/DataStorage/Database/Query/Grammar/Grammar.php
index aa1f18adf..25ce6fc1e 100644
--- a/DataStorage/Database/Query/Grammar/Grammar.php
+++ b/DataStorage/Database/Query/Grammar/Grammar.php
@@ -359,8 +359,6 @@ class Grammar extends GrammarAbstract
             $encoded = \json_encode($value);
 
             return $encoded ? $encoded : 'NULL';
-        } elseif ($value instanceof \Serializable) {
-            return $value->serialize();
         } elseif ($value instanceof Parameter) {
             return $value->__toString();
         } else {
diff --git a/Math/Matrix/Matrix.php b/Math/Matrix/Matrix.php
index 0fd51886b..4846bc398 100644
--- a/Math/Matrix/Matrix.php
+++ b/Math/Matrix/Matrix.php
@@ -736,7 +736,7 @@ class Matrix implements \ArrayAccess, \Iterator
     /**
      * {@inheritdoc}
      */
-    public function offsetExists($offset) : bool
+    public function offsetExists(mixed $offset) : bool
     {
         $row = (int) ($offset / $this->m);
 
diff --git a/Message/Socket/SocketHeader.php b/Message/Socket/SocketHeader.php
index c331f5b75..a858f6bf9 100644
--- a/Message/Socket/SocketHeader.php
+++ b/Message/Socket/SocketHeader.php
@@ -26,7 +26,7 @@ use phpOMS\Message\HeaderAbstract;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-class SocketHeader extends HeaderAbstract implements \Serializable
+class SocketHeader extends HeaderAbstract
 {
     private $sendFrom = null;
 
@@ -199,9 +199,9 @@ class SocketHeader extends HeaderAbstract implements \Serializable
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return $this->__toString();
+        return [];
     }
 
     /**
@@ -225,7 +225,7 @@ class SocketHeader extends HeaderAbstract implements \Serializable
      *
      * @since 1.0.0
      */
-    public function unserialize($string) : void
+    public function __unserialize($string) : void
     {
     }
 
diff --git a/Model/Message/Dom.php b/Model/Message/Dom.php
index e4cc95003..d7a774f96 100644
--- a/Model/Message/Dom.php
+++ b/Model/Message/Dom.php
@@ -24,7 +24,7 @@ use phpOMS\Contract\ArrayableInterface;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-final class Dom implements \Serializable, ArrayableInterface
+final class Dom implements ArrayableInterface
 {
     /**
      * Message type.
@@ -125,13 +125,13 @@ final class Dom implements \Serializable, ArrayableInterface
     /**
      * Render message.
      *
-     * @return string
+     * @return array
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return $this->__toString();
+        return $this->toArray();
     }
 
     /**
@@ -145,7 +145,7 @@ final class Dom implements \Serializable, ArrayableInterface
     /**
      * {@inheritdoc}
      */
-    public function unserialize($raw) : void
+    public function __unserialize($raw) : void
     {
         $unserialized = \json_decode($raw, true);
 
diff --git a/Model/Message/FormValidation.php b/Model/Message/FormValidation.php
index ea9e96732..e695be6c4 100644
--- a/Model/Message/FormValidation.php
+++ b/Model/Message/FormValidation.php
@@ -24,7 +24,7 @@ use phpOMS\Contract\ArrayableInterface;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-final class FormValidation implements \JsonSerializable, \Serializable, ArrayableInterface
+final class FormValidation implements \JsonSerializable, ArrayableInterface
 {
     /**
      * Message type.
@@ -57,13 +57,13 @@ final class FormValidation implements \JsonSerializable, \Serializable, Arrayabl
     /**
      * Render message.
      *
-     * @return string
+     * @return array
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return $this->__toString();
+        return $this->toArray();
     }
 
     /**
@@ -77,7 +77,7 @@ final class FormValidation implements \JsonSerializable, \Serializable, Arrayabl
     /**
      * {@inheritdoc}
      */
-    public function unserialize($raw) : void
+    public function __unserialize($raw) : void
     {
         $unserialized = \json_decode($raw, true);
 
diff --git a/Model/Message/Notify.php b/Model/Message/Notify.php
index 74dc6b062..1b40e0317 100644
--- a/Model/Message/Notify.php
+++ b/Model/Message/Notify.php
@@ -24,7 +24,7 @@ use phpOMS\Contract\ArrayableInterface;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-final class Notify implements \JsonSerializable, \Serializable, ArrayableInterface
+final class Notify implements \JsonSerializable, ArrayableInterface
 {
     /**
      * Message type.
@@ -161,13 +161,13 @@ final class Notify implements \JsonSerializable, \Serializable, ArrayableInterfa
     /**
      * Render message.
      *
-     * @return string
+     * @return array
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return $this->__toString();
+        return $this->toArray();
     }
 
     /**
@@ -181,7 +181,7 @@ final class Notify implements \JsonSerializable, \Serializable, ArrayableInterfa
     /**
      * {@inheritdoc}
      */
-    public function unserialize($raw) : void
+    public function __unserialize($raw) : void
     {
         $unserialized = \json_decode($raw, true);
 
diff --git a/Model/Message/Redirect.php b/Model/Message/Redirect.php
index 70d4478a4..7e19447fd 100644
--- a/Model/Message/Redirect.php
+++ b/Model/Message/Redirect.php
@@ -24,7 +24,7 @@ use phpOMS\Contract\ArrayableInterface;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-final class Redirect implements \JsonSerializable, \Serializable, ArrayableInterface
+final class Redirect implements \JsonSerializable, ArrayableInterface
 {
     /**
      * Message type.
@@ -103,13 +103,13 @@ final class Redirect implements \JsonSerializable, \Serializable, ArrayableInter
     /**
      * Render message.
      *
-     * @return string
+     * @return array
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return $this->__toString();
+        return $this->toArray();
     }
 
     /**
@@ -123,7 +123,7 @@ final class Redirect implements \JsonSerializable, \Serializable, ArrayableInter
     /**
      * {@inheritdoc}
      */
-    public function unserialize($raw) : void
+    public function __unserialize($raw) : void
     {
         $unserialized = \json_decode($raw, true);
 
diff --git a/Model/Message/Reload.php b/Model/Message/Reload.php
index abbcc461c..c2f362c52 100644
--- a/Model/Message/Reload.php
+++ b/Model/Message/Reload.php
@@ -24,7 +24,7 @@ use phpOMS\Contract\ArrayableInterface;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-final class Reload implements \JsonSerializable, \Serializable, ArrayableInterface
+final class Reload implements \JsonSerializable, ArrayableInterface
 {
     /**
      * Message type.
@@ -71,19 +71,19 @@ final class Reload implements \JsonSerializable, \Serializable, ArrayableInterfa
     /**
      * Render message.
      *
-     * @return string
+     * @return array
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return $this->__toString();
+        return $this->toArray();
     }
 
     /**
      * {@inheritdoc}
      */
-    public function unserialize($raw) : void
+    public function __unserialize($raw) : void
     {
         $unserialized = \json_decode($raw, true);
 
diff --git a/Stdlib/Base/FloatInt.php b/Stdlib/Base/FloatInt.php
index 9901bd427..1f8a5e123 100644
--- a/Stdlib/Base/FloatInt.php
+++ b/Stdlib/Base/FloatInt.php
@@ -22,7 +22,7 @@ namespace phpOMS\Stdlib\Base;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-class FloatInt implements \Serializable
+class FloatInt
 {
     /**
      * Max amount of decimals.
@@ -306,9 +306,9 @@ class FloatInt implements \Serializable
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return (string) $this->getInt();
+        return [$this->getInt()];
     }
 
     /**
@@ -320,7 +320,7 @@ class FloatInt implements \Serializable
      *
      * @since 1.0.0
      */
-    public function unserialize($value) : void
+    public function __unserialize($value) : void
     {
         $this->setInt((int) $value);
     }
diff --git a/Stdlib/Base/Iban.php b/Stdlib/Base/Iban.php
index 1d8fb42b4..49e79256e 100644
--- a/Stdlib/Base/Iban.php
+++ b/Stdlib/Base/Iban.php
@@ -24,7 +24,7 @@ use phpOMS\Validation\Finance\IbanEnum;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-class Iban implements \Serializable
+class Iban
 {
     /**
      * Iban.
@@ -254,9 +254,9 @@ class Iban implements \Serializable
     /**
      * {@inheritdoc}
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return $this->prettyPrint();
+        return [$this->prettyPrint()];
     }
 
     /**
@@ -280,7 +280,7 @@ class Iban implements \Serializable
      * @return void
      * @since 5.1.0
      */
-    public function unserialize($serialized) : void
+    public function __unserialize($serialized) : void
     {
         $this->parse($serialized);
     }
diff --git a/Stdlib/Base/Location.php b/Stdlib/Base/Location.php
index 868ce7d58..e20b7898c 100644
--- a/Stdlib/Base/Location.php
+++ b/Stdlib/Base/Location.php
@@ -24,7 +24,7 @@ use phpOMS\Localization\ISO3166TwoEnum;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-class Location implements \JsonSerializable, \Serializable
+class Location implements \JsonSerializable
 {
     /**
      * Location id
@@ -183,9 +183,9 @@ class Location implements \JsonSerializable, \Serializable
     /**
      * {@inheritdoc}
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return (string) \json_encode($this->jsonSerialize());
+        return $this->toArray();
     }
 
     /**
@@ -214,7 +214,7 @@ class Location implements \JsonSerializable, \Serializable
     /**
      * {@inheritdoc}
      */
-    public function unserialize($serialized) : void
+    public function __unserialize($serialized) : void
     {
         $data = \json_decode($serialized, true);
 
diff --git a/Stdlib/Queue/PriorityQueue.php b/Stdlib/Queue/PriorityQueue.php
index a40b569c2..6f97f8743 100644
--- a/Stdlib/Queue/PriorityQueue.php
+++ b/Stdlib/Queue/PriorityQueue.php
@@ -24,7 +24,7 @@ use phpOMS\Stdlib\Base\Exception\InvalidEnumValue;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-class PriorityQueue implements \Countable, \Serializable
+class PriorityQueue implements \Countable
 {
     /**
      * Queue type.
@@ -313,9 +313,9 @@ class PriorityQueue implements \Countable, \Serializable
     /**
      * {@inheritdoc}
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        return (string) \json_encode($this->queue);
+        return $this->queue;
     }
 
     /**
@@ -327,7 +327,7 @@ class PriorityQueue implements \Countable, \Serializable
      *
      * @since 1.0.0
      */
-    public function unserialize($data) : void
+    public function __unserialize($data) : void
     {
         $this->queue = \json_decode($data, true);
     }
diff --git a/System/File/Ftp/Directory.php b/System/File/Ftp/Directory.php
index 6a40c3d70..d0c523b32 100644
--- a/System/File/Ftp/Directory.php
+++ b/System/File/Ftp/Directory.php
@@ -728,7 +728,7 @@ class Directory extends FileAbstract implements DirectoryInterface
     /**
      * {@inheritdoc}
      */
-    public function offsetExists($offset) : bool
+    public function offsetExists(mixed $offset) : bool
     {
         $offset = isset($this->nodes[$offset]) ? $offset : $this->path . '/' . $offset;
 
diff --git a/System/File/Local/Directory.php b/System/File/Local/Directory.php
index 756c7eb91..2d660686f 100644
--- a/System/File/Local/Directory.php
+++ b/System/File/Local/Directory.php
@@ -551,7 +551,7 @@ final class Directory extends FileAbstract implements DirectoryInterface
     /**
      * {@inheritdoc}
      */
-    public function offsetExists($offset) : bool
+    public function offsetExists(mixed $offset) : bool
     {
         $offset = isset($this->nodes[$offset]) ? $offset : $this->path . '/' . $offset;
 
diff --git a/Utils/Parser/Php/ArrayParser.php b/Utils/Parser/Php/ArrayParser.php
index 8d9e8210c..1f9cc06be 100644
--- a/Utils/Parser/Php/ArrayParser.php
+++ b/Utils/Parser/Php/ArrayParser.php
@@ -77,8 +77,6 @@ class ArrayParser
             return \rtrim(\rtrim(\number_format($value, 5, '.', ''), '0'), '.');
         } elseif (\is_scalar($value)) {
             return (string) $value;
-        } elseif ($value instanceof \Serializable) {
-            return self::parseVariable($value->serialize());
         } elseif ($value instanceof \JsonSerializable) {
             return self::parseVariable($value->jsonSerialize());
         } else {
diff --git a/Utils/StringUtils.php b/Utils/StringUtils.php
index 1b0d13b60..db7da5b0b 100644
--- a/Utils/StringUtils.php
+++ b/Utils/StringUtils.php
@@ -200,8 +200,6 @@ final class StringUtils
             $encoded = \json_encode($element, $option !== null ? $option : 0);
 
             return $encoded ? $encoded : null;
-        } elseif ($element instanceof \Serializable) {
-            return $element->serialize();
         } elseif (\is_string($element)) {
             return $element;
         } elseif (\is_int($element) || \is_float($element)) {
diff --git a/Utils/TaskSchedule/Interval.php b/Utils/TaskSchedule/Interval.php
index da67921ac..548c0bfef 100644
--- a/Utils/TaskSchedule/Interval.php
+++ b/Utils/TaskSchedule/Interval.php
@@ -22,7 +22,7 @@ namespace phpOMS\Utils\TaskSchedule;
  * @link    https://karaka.app
  * @since   1.0.0
  */
-class Interval implements \Serializable
+class Interval
 {
     /**
      * Start of the task.
@@ -520,13 +520,13 @@ class Interval implements \Serializable
     /**
      * Create string representation.
      *
-     * @return string
+     * @return array
      *
      * @since 1.0.0
      */
-    public function serialize() : string
+    public function __serialize() : array
     {
-        $serialized = \json_encode([
+        return [
             'start'       => $this->start->format('Y-m-d H:i:s'),
             'end'         => $this->end === null ? null : $this->end->format('Y-m-d H:i:s'),
             'maxDuration' => $this->maxDuration,
@@ -535,9 +535,7 @@ class Interval implements \Serializable
             'dayOfMonth'  => $this->dayOfMonth,
             'dayOfWeek'   => $this->dayOfWeek,
             'year'        => $this->year,
-        ]);
-
-        return $serialized === false ? '{}' : $serialized;
+        ];
     }
 
     /**
@@ -549,7 +547,7 @@ class Interval implements \Serializable
      *
      * @since 1.0.0
      */
-    public function unserialize($serialized) : void
+    public function __unserialize($serialized) : void
     {
         $data = \json_decode($serialized, true);
 
diff --git a/tests/DataStorage/Cache/Connection/FileCacheSerializable.php b/tests/DataStorage/Cache/Connection/FileCacheSerializable.php
index 8534b0691..3a89e527e 100755
--- a/tests/DataStorage/Cache/Connection/FileCacheSerializable.php
+++ b/tests/DataStorage/Cache/Connection/FileCacheSerializable.php
@@ -14,16 +14,16 @@ declare(strict_types=1);
 
 namespace phpOMS\tests\DataStorage\Cache\Connection;
 
-class FileCacheSerializable implements \Serializable
+class FileCacheSerializable
 {
     public $val = 'asdf';
 
-    public function serialize()
+    public function __serialize()
     {
-        return 'abc';
+        return ['abc'];
     }
 
-    public function unserialize($val) : void
+    public function __unserialize($val) : void
     {
         $this->val = $val;
     }
diff --git a/tests/DataStorage/Database/TestModel/BaseModel.php b/tests/DataStorage/Database/TestModel/BaseModel.php
index 5bdaaab66..872b0a981 100755
--- a/tests/DataStorage/Database/TestModel/BaseModel.php
+++ b/tests/DataStorage/Database/TestModel/BaseModel.php
@@ -65,15 +65,15 @@ class BaseModel
         $this->ownsOneSelf  = new OwnsOneModel();
         $this->belongsToOne = new BelongsToModel();
 
-        $this->serializable = new class() implements \Serializable {
+        $this->serializable = new class() {
             public $value = '';
 
-            public function serialize()
+            public function __serialize()
             {
-                return '123';
+                return ['123'];
             }
 
-            public function unserialize($data) : void
+            public function __unserialize($data) : void
             {
                 $this->value = $data;
             }
diff --git a/tests/Utils/Parser/Php/ArrayParserTest.php b/tests/Utils/Parser/Php/ArrayParserTest.php
index 1bda69619..45288b8aa 100644
--- a/tests/Utils/Parser/Php/ArrayParserTest.php
+++ b/tests/Utils/Parser/Php/ArrayParserTest.php
@@ -30,12 +30,6 @@ final class ArrayParserTest extends \PHPUnit\Framework\TestCase
      */
     public function testParser() : void
     {
-        $serializable = new class() implements \Serializable {
-            public function serialize() { return 2; }
-
-            public function unserialize($raw) : void {}
-        };
-
         $jsonSerialize = new class() implements \JsonSerializable {
             public function jsonSerialize() { return [6, 7]; }
         };
@@ -50,7 +44,6 @@ final class ArrayParserTest extends \PHPUnit\Framework\TestCase
                 0 => 'a',
                 1 => 'b',
             ],
-            5 => $serializable,
             6 => $jsonSerialize,
         ];
 
@@ -64,7 +57,6 @@ final class ArrayParserTest extends \PHPUnit\Framework\TestCase
                 0 => 'a',
                 1 => 'b',
             ],
-            5 => $serializable->serialize(),
             6 => $jsonSerialize->jsonSerialize(),
         ];
 
diff --git a/tests/Utils/StringUtilsTest.php b/tests/Utils/StringUtilsTest.php
index 630cfe016..9a57f0207 100644
--- a/tests/Utils/StringUtilsTest.php
+++ b/tests/Utils/StringUtilsTest.php
@@ -130,17 +130,6 @@ final class StringUtilsTest extends \PHPUnit\Framework\TestCase
 
         self::assertEquals('["abc"]', StringUtils::stringify(['abc']));
 
-        self::assertEquals('abc', StringUtils::stringify(new class() implements \Serializable {
-            public function serialize()
-            {
-                return 'abc';
-            }
-
-            public function unserialize($val) : void
-            {
-            }
-        }));
-
         self::assertEquals('abc', StringUtils::stringify('abc'));
         self::assertEquals('1', StringUtils::stringify(1));
         self::assertEquals('1.1', StringUtils::stringify(1.1));