diff --git a/src/Enum.php b/src/Enum.php
index b0d764f..81c7821 100644
--- a/src/Enum.php
+++ b/src/Enum.php
@@ -18,7 +18,9 @@
 class Enum implements EnumInterface
 {
     /** @var array */
-    private static array $constants;
+    private static array $constants = [];
+
+    protected static array $instances = [];
 
     /** @var mixed */
     private mixed $value;
@@ -33,11 +35,10 @@ class Enum implements EnumInterface
      */
     final public function __construct(mixed $value)
     {
-        static::$constants = static::constants();
-
         $value = ($value instanceof EnumInterface) ? $value->getValue() : $value;
 
         $this->key = static::searchNameByValue($value);
+
         $this->value = $value;
     }
 
@@ -46,9 +47,15 @@ final public function __construct(mixed $value)
      */
     private static function constants(): array
     {
+        if (isset(static::$constants[static::class])) {
+            return static::$constants[static::class];
+        }
+
         $reflection = new ReflectionClass(static::class);
 
-        return $reflection->getConstants();
+        static::$constants[static::class] =  $reflection->getConstants();
+
+        return static::$constants[static::class];
     }
 
     /**
@@ -65,7 +72,7 @@ public function getValue(): mixed
      */
     private static function searchNameByValue(mixed $value): string
     {
-        $name = array_search($value, static::$constants, true);
+        $name = array_search($value, static::constants(), true);
         if (false === $name) {
             throw new InvalidArgumentException(sprintf('Constant value [%s] not found', $value));
         }
@@ -80,11 +87,16 @@ private static function searchNameByValue(mixed $value): string
      */
     final public static function __callStatic(string $name, array $arguments): self
     {
-        if (!array_key_exists($name, static::$constants)) {
+        if (!array_key_exists($name, static::constants())) {
             throw new InvalidArgumentException(sprintf('Constant [%s] is not defined', $name));
         }
+        if (isset(static::$instances[static::class][$name])) {
+            return static::$instances[static::class][$name];
+        }
+
+        static::$instances[static::class][$name] = new static(static::constants()[$name]);
 
-        return new static(static::$constants[$name]);
+        return static::$instances[static::class][$name];
     }
 
     /**
@@ -92,7 +104,7 @@ final public static function __callStatic(string $name, array $arguments): self
      */
     public function getValues(): array
     {
-        return array_values(static::$constants);
+        return array_values(static::$constants[static::class]);
     }
 
     /**
@@ -100,7 +112,7 @@ public function getValues(): array
      */
     public function getKeys(): array
     {
-        return array_keys(static::$constants);
+        return array_keys(static::$constants[static::class]);
     }
 
     /**
@@ -116,7 +128,7 @@ public function getKey(): string
      */
     public function toArray(): array
     {
-        return static::$constants;
+        return static::$constants[static::class];
     }
 
     /**
diff --git a/tests/EnumTest.php b/tests/EnumTest.php
index f04ed0a..6bbc736 100644
--- a/tests/EnumTest.php
+++ b/tests/EnumTest.php
@@ -53,7 +53,7 @@ public function invalidMethod(): void
     public function keysValues(): void
     {
         $this->enum = new DummyEnum(5);
-        static::assertEquals(["VALUE", "OTHER", "PRODUCT"], $this->enum->getKeys());
+        static::assertEquals(["VALUE1", "VALUE2", "VALUE5"], $this->enum->getKeys());
         static::assertEquals([0 => 1, 1=> 2, 2=> 5], $this->enum->getValues());
     }
 
@@ -66,22 +66,22 @@ public function callDataProvider(): array
 
         return [
             [
-                "1", $this->enum::VALUE()
+                "1", $this->enum::VALUE1()
             ],
             [
-                "2", $this->enum::OTHER(),
+                "2", $this->enum::VALUE2(),
             ],
             [
                 "5", new DummyEnum(new DummyEnum(5)),
             ],
             [
-                5, $this->enum->getValue(),
+                "5", $this->enum->getValue(),
             ],
             [
-                "PRODUCT", $this->enum->getKey(),
+                "VALUE5", $this->enum->getKey(),
             ],
             [
-                ["VALUE" => 1, "OTHER" => 2, "PRODUCT" => 5], $this->enum->toArray(),
+                ["VALUE1" => 1, "VALUE2" => 2, "VALUE5" => 5], $this->enum->toArray(),
             ]
         ];
     }
@@ -96,9 +96,9 @@ public function callDataProvider(): array
  */
 class DummyEnum extends Enum
 {
-    public const VALUE = 1;
+    public const VALUE1 = 1;
 
-    public const OTHER = 2;
+    public const VALUE2 = 2;
 
-    public const PRODUCT = 5;
+    public const VALUE5 = 5;
 }