diff --git a/src/Enum.php b/src/Enum.php
index 3790f6e..b665b0c 100644
--- a/src/Enum.php
+++ b/src/Enum.php
@@ -28,6 +28,13 @@ abstract class Enum implements \JsonSerializable
      */
     protected $value;
 
+    /**
+     * Enum key, the constant name
+     *
+     * @var string
+     */
+    private $key;
+
     /**
      * Store existing constants in a static cache per object.
      *
@@ -61,12 +68,19 @@ public function __construct($value)
             $value = $value->getValue();
         }
 
-        static::assertValidValue($value);
+        $this->key = static::assertValidValueReturningKey($value);
 
         /** @psalm-var T */
         $this->value = $value;
     }
 
+    public function __wakeup()
+    {
+        if ($this->key === null) {
+            $this->key = static::search($this->value);
+        }
+    }
+
     /**
      * @param mixed $value
      * @return static
@@ -74,9 +88,9 @@ public function __construct($value)
      */
     public static function from($value): self
     {
-        static::assertValidValue($value);
+        $key = static::assertValidValueReturningKey($value);
 
-        return new static($value);
+        return self::__callStatic($key, []);
     }
 
     /**
@@ -93,11 +107,11 @@ public function getValue()
      * Returns the enum key (i.e. the constant name).
      *
      * @psalm-pure
-     * @return mixed
+     * @return string
      */
     public function getKey()
     {
-        return static::search($this->value);
+        return $this->key;
     }
 
     /**
@@ -201,9 +215,22 @@ public static function isValid($value)
      */
     public static function assertValidValue($value): void
     {
-        if (!static::isValid($value)) {
+        self::assertValidValueReturningKey($value);
+    }
+
+    /**
+     * Asserts valid enum value
+     *
+     * @psalm-pure
+     * @psalm-assert T $value
+     */
+    private static function assertValidValueReturningKey($value): string
+    {
+        if (false === ($key = static::search($value))) {
             throw new \UnexpectedValueException("Value '$value' is not part of the enum " . static::class);
         }
+
+        return $key;
     }
 
     /**
@@ -224,11 +251,11 @@ public static function isValidKey($key)
     /**
      * Return key for value
      *
-     * @param $value
+     * @param mixed $value
      *
      * @psalm-param mixed $value
      * @psalm-pure
-     * @return mixed
+     * @return string|false
      */
     public static function search($value)
     {
diff --git a/tests/EnumTest.php b/tests/EnumTest.php
index 674b977..154b8ba 100755
--- a/tests/EnumTest.php
+++ b/tests/EnumTest.php
@@ -60,6 +60,14 @@ public function testFailToCreateEnumWithInvalidValueThroughNamedConstructor($val
         EnumFixture::from($value);
     }
 
+    public function testFailToCreateEnumWithEnumItselfThroughNamedConstructor(): void
+    {
+        $this->expectException(\UnexpectedValueException::class);
+        $this->expectExceptionMessage("Value 'foo' is not part of the enum " . EnumFixture::class);
+
+        EnumFixture::from(EnumFixture::FOO());
+    }
+
     /**
      * Contains values not existing in EnumFixture
      * @return array
@@ -316,12 +324,13 @@ public function testSerialize()
     {
         // split string for Pretty CI: "Line exceeds 120 characters"
         $bin = '4f3a33303a224d79434c6162735c54657374735c456e756d5c456e756d4669787'.
-            '4757265223a313a7b733a383a22002a0076616c7565223b733a333a22666f6f223b7d';
+            '4757265223a323a7b733a383a22002a0076616c7565223b733a333a22666f6f223b73'.
+            '3a32323a22004d79434c6162735c456e756d5c456e756d006b6579223b733a333a22464f4f223b7d';
 
         $this->assertEquals($bin, bin2hex(serialize(EnumFixture::FOO())));
     }
 
-    public function testUnserialize()
+    public function testUnserializeVersionWithoutKey()
     {
         // split string for Pretty CI: "Line exceeds 120 characters"
         $bin = '4f3a33303a224d79434c6162735c54657374735c456e756d5c456e756d4669787'.
@@ -332,6 +341,22 @@ public function testUnserialize()
 
         $this->assertEquals(EnumFixture::FOO, $value->getValue());
         $this->assertTrue(EnumFixture::FOO()->equals($value));
+        $this->assertTrue(EnumFixture::FOO() == $value);
+    }
+
+    public function testUnserialize()
+    {
+        // split string for Pretty CI: "Line exceeds 120 characters"
+        $bin = '4f3a33303a224d79434c6162735c54657374735c456e756d5c456e756d4669787'.
+            '4757265223a323a7b733a383a22002a0076616c7565223b733a333a22666f6f223b73'.
+            '3a32323a22004d79434c6162735c456e756d5c456e756d006b6579223b733a333a22464f4f223b7d';
+
+        /* @var $value EnumFixture */
+        $value = unserialize(pack('H*', $bin));
+
+        $this->assertEquals(EnumFixture::FOO, $value->getValue());
+        $this->assertTrue(EnumFixture::FOO()->equals($value));
+        $this->assertTrue(EnumFixture::FOO() == $value);
     }
 
     /**