diff --git a/README.md b/README.md
index c806228..c39818d 100644
--- a/README.md
+++ b/README.md
@@ -230,12 +230,33 @@ use Savks\Negotiator\Support\DTO\{
 
 new Intersection(
     new UserMapper($this->user),
-    new ObjectValue( $this->user, fn (Factory $factory) => [
+    new ObjectValue($this->user, fn (Factory $factory) => [
         'otherField' => $factory->string('other_field')
     ]),
 );
 ```
 
+* `oneOfConst` — дозволяє вказати, що значення може набувати одного з типів-констант. Приклад:
+
+```php
+<?php
+
+use App\Models\User;
+
+use Savks\Negotiator\Support\DTO\{
+    Utils\Factory,
+    ObjectValue
+};
+
+new ObjectValue($this->source, fn (Factory $factory) => [
+    'field' => $factory->oneOfConst([
+        $factory->constNumber(1),
+        $factory->constNumber(2),
+        $factory->constNumber(3),
+    ]),
+]);
+```
+
 ## Генерація типів
 
 Для генерації типів пакет містить клас генератора `Savks\Negotiator\Support\TypeGeneration\Generator`. Для роботи якого достатньо вказання для яких маперів і з якими просторами імен потрібно згенерувати код. Приклад використання:
diff --git a/src/Support/DTO/Castable.php b/src/Support/DTO/Castable.php
index 6e1b0f9..ec103fc 100644
--- a/src/Support/DTO/Castable.php
+++ b/src/Support/DTO/Castable.php
@@ -153,4 +153,12 @@ public function null(): NullValue
     {
         return new NullValue();
     }
+
+    /**
+     * @param list<ConstBooleanValue|ConstEnumValue|ConstNumberValue|ConstStringValue> $values
+     */
+    public function oneOfConst(array $values, string|Closure|null $accessor = null): OneOfConstValue
+    {
+        return new OneOfConstValue($this->source, $values, $accessor);
+    }
 }
diff --git a/src/Support/DTO/ConstBooleanValue.php b/src/Support/DTO/ConstBooleanValue.php
index 6ada98f..b5e5b88 100644
--- a/src/Support/DTO/ConstBooleanValue.php
+++ b/src/Support/DTO/ConstBooleanValue.php
@@ -7,7 +7,10 @@
     ConstBooleanType
 };
 
-class ConstBooleanValue extends Value
+/**
+ * @extends ConstValue<bool>
+ */
+class ConstBooleanValue extends ConstValue
 {
     public function __construct(
         protected readonly bool $value,
@@ -15,6 +18,11 @@ public function __construct(
     ) {
     }
 
+    public function originalValue(): bool
+    {
+        return $this->value;
+    }
+
     protected function finalize(): bool
     {
         return $this->value;
diff --git a/src/Support/DTO/ConstEnumValue.php b/src/Support/DTO/ConstEnumValue.php
index 8a01598..38cd414 100644
--- a/src/Support/DTO/ConstEnumValue.php
+++ b/src/Support/DTO/ConstEnumValue.php
@@ -3,9 +3,10 @@
 namespace Savks\Negotiator\Support\DTO;
 
 use BackedEnum;
+use ReflectionEnum;
+use ReflectionNamedType;
 use Savks\Negotiator\Contexts\TypeGenerationContext;
 use Savks\PhpContexts\Context;
-use StringBackedEnum;
 
 use Savks\Negotiator\Support\Types\{
     AliasType,
@@ -13,12 +14,17 @@
     StringType
 };
 
-class ConstEnumValue extends NullableValue
+class ConstEnumValue extends ConstValue
 {
-    public function __construct(protected BackedEnum $case)
+    public function __construct(protected readonly BackedEnum $case)
     {
     }
 
+    public function originalValue(): BackedEnum
+    {
+        return $this->case;
+    }
+
     protected function finalize(): string|int|null
     {
         return $this->case->value;
@@ -26,14 +32,18 @@ protected function finalize(): string|int|null
 
     protected function types(): AliasType|StringType|NumberType
     {
-        $enumRef = Context::use(TypeGenerationContext::class)->resolveEnumRef(
-            $this->case::class
-        );
+        /** @var TypeGenerationContext $typeGenerationContext */
+        $typeGenerationContext = Context::use(TypeGenerationContext::class);
+
+        $enumRef = $typeGenerationContext->resolveEnumRef($this->case::class);
 
         if ($enumRef) {
             return new AliasType("{$enumRef}.{$this->case->name}");
         }
 
-        return $this->case instanceof StringBackedEnum ? new StringType() : new NumberType();
+        /** @var ReflectionNamedType $type */
+        $type = (new ReflectionEnum($this->case))->getBackingType();
+
+        return $type->getName() === 'string' ? new StringType() : new NumberType();
     }
 }
diff --git a/src/Support/DTO/ConstNumberValue.php b/src/Support/DTO/ConstNumberValue.php
index 7c4695f..cc0e61f 100644
--- a/src/Support/DTO/ConstNumberValue.php
+++ b/src/Support/DTO/ConstNumberValue.php
@@ -7,7 +7,7 @@
     NumberType
 };
 
-class ConstNumberValue extends Value
+class ConstNumberValue extends ConstValue
 {
     public function __construct(
         protected readonly int|float $value,
@@ -15,6 +15,11 @@ public function __construct(
     ) {
     }
 
+    public function originalValue(): int|float
+    {
+        return $this->value;
+    }
+
     protected function finalize(): int|float
     {
         return $this->value;
diff --git a/src/Support/DTO/ConstStringValue.php b/src/Support/DTO/ConstStringValue.php
index bfefb56..2f7a8f0 100644
--- a/src/Support/DTO/ConstStringValue.php
+++ b/src/Support/DTO/ConstStringValue.php
@@ -7,7 +7,7 @@
     StringType
 };
 
-class ConstStringValue extends Value
+class ConstStringValue extends ConstValue
 {
     public function __construct(
         protected readonly string $value,
@@ -15,6 +15,11 @@ public function __construct(
     ) {
     }
 
+    public function originalValue(): string
+    {
+        return $this->value;
+    }
+
     protected function finalize(): string
     {
         return $this->value;
diff --git a/src/Support/DTO/ConstValue.php b/src/Support/DTO/ConstValue.php
new file mode 100644
index 0000000..6a6ef79
--- /dev/null
+++ b/src/Support/DTO/ConstValue.php
@@ -0,0 +1,14 @@
+<?php
+
+namespace Savks\Negotiator\Support\DTO;
+
+/**
+ * @template TOriginalValueType
+ */
+abstract class ConstValue extends Value
+{
+    /**
+     * @return TOriginalValueType
+     */
+    abstract public function originalValue(): mixed;
+}
diff --git a/src/Support/DTO/OneOfConstValue.php b/src/Support/DTO/OneOfConstValue.php
new file mode 100644
index 0000000..73ac8fa
--- /dev/null
+++ b/src/Support/DTO/OneOfConstValue.php
@@ -0,0 +1,101 @@
+<?php
+
+namespace Savks\Negotiator\Support\DTO;
+
+use BackedEnum;
+use Closure;
+use RuntimeException;
+use Savks\Negotiator\Exceptions\UnexpectedValue;
+
+use Savks\Negotiator\Support\Types\{
+    BooleanType,
+    ConstBooleanType,
+    ConstNumberType,
+    ConstStringType,
+    NumberType,
+    StringType,
+    Types
+};
+
+class OneOfConstValue extends NullableValue
+{
+    /**
+     * @param ConstValue[] $values
+     */
+    public function __construct(
+        protected readonly mixed $source,
+        protected readonly array $values,
+        protected readonly string|Closure|null $accessor = null
+    ) {
+    }
+
+    protected function finalize(): string|int|float|bool|null
+    {
+        $value = $this->resolveValueFromAccessor(
+            $this->accessor,
+            $this->source,
+            $this->sourcesTrace
+        );
+
+        if ($this->accessor && last($this->sourcesTrace) !== $this->source) {
+            $this->sourcesTrace[] = $this->source;
+        }
+
+        if ($value === null) {
+            return null;
+        }
+
+        $isMatched = null;
+
+        foreach ($this->values as $constValue) {
+            $isMatched = $constValue->originalValue() === $value;
+
+            if ($isMatched) {
+                break;
+            }
+        }
+
+        if (! $isMatched) {
+            $types = [];
+
+            foreach ($this->values as $constValue) {
+                if ($constValue instanceof ConstEnumValue) {
+                    $types[] = 'BackedEnum<' . $constValue->originalValue()::class . '>';
+                } else {
+                    foreach ($constValue->compileTypes()->types as $type) {
+                        $types[] = match (true) {
+                            $type instanceof ConstBooleanType => $type->value ? 'true' : 'false',
+
+                            $type instanceof ConstNumberType, $type instanceof ConstStringType => $type->value,
+
+                            $type instanceof BooleanType => 'bool',
+                            $type instanceof NumberType => 'numeric',
+                            $type instanceof StringType => 'string',
+
+                            default => throw new RuntimeException(
+                                \sprintf('Unprocessed type "%s".', $type::class)
+                            )
+                        };
+                    }
+                }
+            }
+
+            throw new UnexpectedValue($types, $value);
+        }
+
+        return $value instanceof BackedEnum ? $value->value : $value;
+    }
+
+    protected function types(): Types
+    {
+        $types = [];
+
+        foreach ($this->values as $value) {
+            $types[] = $value->compileTypes()->types;
+        }
+
+        return new Types(
+            \array_merge(...$types)
+        );
+    }
+}