diff --git a/src/Mappers/Root/CompoundTypeMapper.php b/src/Mappers/Root/CompoundTypeMapper.php
index ed9f995873..70323ae80a 100644
--- a/src/Mappers/Root/CompoundTypeMapper.php
+++ b/src/Mappers/Root/CompoundTypeMapper.php
@@ -23,6 +23,7 @@
 use RuntimeException;
 use TheCodingMachine\GraphQLite\Mappers\CannotMapTypeException;
 use TheCodingMachine\GraphQLite\Mappers\RecursiveTypeMapperInterface;
+use TheCodingMachine\GraphQLite\NamingStrategyInterface;
 use TheCodingMachine\GraphQLite\TypeRegistry;
 use TheCodingMachine\GraphQLite\Types\UnionType;
 
@@ -38,8 +39,13 @@
  */
 class CompoundTypeMapper implements RootTypeMapperInterface
 {
-    public function __construct(private RootTypeMapperInterface $next, private RootTypeMapperInterface $topRootTypeMapper, private TypeRegistry $typeRegistry, private RecursiveTypeMapperInterface $recursiveTypeMapper)
-    {
+    public function __construct(
+        private RootTypeMapperInterface $next,
+        private RootTypeMapperInterface $topRootTypeMapper,
+        private NamingStrategyInterface $namingStrategy,
+        private TypeRegistry $typeRegistry,
+        private RecursiveTypeMapperInterface $recursiveTypeMapper,
+    ) {
     }
 
     public function toGraphQLOutputType(Type $type, OutputType|null $subType, ReflectionMethod|ReflectionProperty $reflector, DocBlock $docBlockObj): OutputType
@@ -144,7 +150,7 @@ private function getTypeFromUnion(array $unionTypes): GraphQLType
                 throw CannotMapTypeException::createForBadTypeInUnion($unionTypes);
             }
 
-            $graphQlType = new UnionType($nonNullableUnionTypes, $this->recursiveTypeMapper);
+            $graphQlType = new UnionType($nonNullableUnionTypes, $this->recursiveTypeMapper, $this->namingStrategy);
             $graphQlType = $this->typeRegistry->getOrRegisterType($graphQlType);
             assert($graphQlType instanceof UnionType);
         }
diff --git a/src/NamingStrategy.php b/src/NamingStrategy.php
index ecb82b21a0..bb308dbb73 100644
--- a/src/NamingStrategy.php
+++ b/src/NamingStrategy.php
@@ -8,6 +8,7 @@
 use TheCodingMachine\GraphQLite\Annotations\Input;
 use TheCodingMachine\GraphQLite\Annotations\TypeInterface;
 
+use function implode;
 use function lcfirst;
 use function str_ends_with;
 use function str_replace;
@@ -109,4 +110,14 @@ public function getInputFieldNameFromMethodName(string $methodName): string
 
         return $methodName;
     }
+
+    /**
+     * Returns the name of a GraphQL union type based on the included types.
+     *
+     * @param string[] $typeNames The list of GraphQL type names
+     */
+    public function getUnionTypeName(array $typeNames): string
+    {
+        return 'Union' . implode('', $typeNames);
+    }
 }
diff --git a/src/NamingStrategyInterface.php b/src/NamingStrategyInterface.php
index aee6f61eb9..c1e29cf74d 100644
--- a/src/NamingStrategyInterface.php
+++ b/src/NamingStrategyInterface.php
@@ -44,4 +44,11 @@ public function getFieldNameFromMethodName(string $methodName): string;
      * Returns the name of a GraphQL input field from the name of the annotated method.
      */
     public function getInputFieldNameFromMethodName(string $methodName): string;
+
+    /**
+     * Returns the name of a GraphQL union type based on the included types.
+     *
+     * @param string[] $typeNames The list of GraphQL type names
+     */
+    public function getUnionTypeName(array $typeNames): string;
 }
diff --git a/src/SchemaFactory.php b/src/SchemaFactory.php
index abaac63745..b7dac89888 100644
--- a/src/SchemaFactory.php
+++ b/src/SchemaFactory.php
@@ -407,7 +407,7 @@ public function createSchema(): Schema
             }
         }
 
-        $rootTypeMapper = new CompoundTypeMapper($rootTypeMapper, $topRootTypeMapper, $typeRegistry, $recursiveTypeMapper);
+        $rootTypeMapper = new CompoundTypeMapper($rootTypeMapper, $topRootTypeMapper, $namingStrategy, $typeRegistry, $recursiveTypeMapper);
         $rootTypeMapper = new IteratorTypeMapper($rootTypeMapper, $topRootTypeMapper);
 
         $topRootTypeMapper->setNext($rootTypeMapper);
diff --git a/src/Types/UnionType.php b/src/Types/UnionType.php
index b923ea2211..30aaf0ef8a 100644
--- a/src/Types/UnionType.php
+++ b/src/Types/UnionType.php
@@ -7,22 +7,31 @@
 use GraphQL\Type\Definition\ObjectType;
 use InvalidArgumentException;
 use TheCodingMachine\GraphQLite\Mappers\RecursiveTypeMapperInterface;
+use TheCodingMachine\GraphQLite\NamingStrategyInterface;
 
+use function array_map;
 use function gettype;
 use function is_object;
 
 class UnionType extends \GraphQL\Type\Definition\UnionType
 {
     /** @param array<int,ObjectType> $types */
-    public function __construct(array $types, RecursiveTypeMapperInterface $typeMapper)
+    public function __construct(
+        array $types,
+        RecursiveTypeMapperInterface $typeMapper,
+        NamingStrategyInterface $namingStrategy,
+    )
     {
-        $name = 'Union';
+        // Make sure all types are object types
         foreach ($types as $type) {
-            $name .= $type->name;
             if (! $type instanceof ObjectType) {
                 throw InvalidTypesInUnionException::notObjectType();
             }
         }
+
+        $typeNames = array_map(static fn (ObjectType $type) => $type->name, $types);
+        $name = $namingStrategy->getUnionTypeName($typeNames);
+
         parent::__construct([
             'name' => $name,
             'types' => $types,
diff --git a/tests/AbstractQueryProviderTest.php b/tests/AbstractQueryProviderTest.php
index 2970f7cf6a..2c1ba84bc8 100644
--- a/tests/AbstractQueryProviderTest.php
+++ b/tests/AbstractQueryProviderTest.php
@@ -351,6 +351,7 @@ protected function buildRootTypeMapper(): RootTypeMapperInterface
         $rootTypeMapper = new CompoundTypeMapper(
             $rootTypeMapper,
             $topRootTypeMapper,
+            new NamingStrategy(),
             $this->getTypeRegistry(),
             $this->getTypeMapper()
         );
diff --git a/tests/Integration/EndToEndTest.php b/tests/Integration/EndToEndTest.php
index c5756cc58b..b1f75ee64f 100644
--- a/tests/Integration/EndToEndTest.php
+++ b/tests/Integration/EndToEndTest.php
@@ -296,7 +296,7 @@ public function createContainer(array $overloadedServices = []): ContainerInterf
                 if (interface_exists(UnitEnum::class)) {
                     $rootTypeMapper = new EnumTypeMapper($rootTypeMapper, $container->get(AnnotationReader::class), new ArrayAdapter(), [ $container->get(NamespaceFactory::class)->createNamespace('TheCodingMachine\\GraphQLite\\Fixtures81\\Integration\\Models') ]);
                 }
-                $rootTypeMapper = new CompoundTypeMapper($rootTypeMapper, $container->get(RootTypeMapperInterface::class), $container->get(TypeRegistry::class), $container->get(RecursiveTypeMapperInterface::class));
+                $rootTypeMapper = new CompoundTypeMapper($rootTypeMapper, $container->get(RootTypeMapperInterface::class), $container->get(NamingStrategyInterface::class), $container->get(TypeRegistry::class), $container->get(RecursiveTypeMapperInterface::class));
                 $rootTypeMapper = new IteratorTypeMapper($rootTypeMapper, $container->get(RootTypeMapperInterface::class));
                 return $rootTypeMapper;
             },
diff --git a/tests/Mappers/Root/CompoundTypeMapperTest.php b/tests/Mappers/Root/CompoundTypeMapperTest.php
index 0f5dbd0360..ae36608d9f 100644
--- a/tests/Mappers/Root/CompoundTypeMapperTest.php
+++ b/tests/Mappers/Root/CompoundTypeMapperTest.php
@@ -11,6 +11,7 @@
 use RuntimeException;
 use TheCodingMachine\GraphQLite\AbstractQueryProviderTest;
 use TheCodingMachine\GraphQLite\Mappers\CannotMapTypeException;
+use TheCodingMachine\GraphQLite\NamingStrategy;
 
 class CompoundTypeMapperTest extends AbstractQueryProviderTest
 {
@@ -19,6 +20,7 @@ public function testException1()
         $compoundTypeMapper = new CompoundTypeMapper(
             new FinalRootTypeMapper($this->getTypeMapper()),
             new FinalRootTypeMapper($this->getTypeMapper()),
+            new NamingStrategy(),
             $this->getTypeRegistry(),
             $this->getTypeMapper()
         );
@@ -32,6 +34,7 @@ public function testException2()
         $compoundTypeMapper = new CompoundTypeMapper(
             new FinalRootTypeMapper($this->getTypeMapper()),
             new FinalRootTypeMapper($this->getTypeMapper()),
+            new NamingStrategy(),
             $this->getTypeRegistry(),
             $this->getTypeMapper()
         );
diff --git a/tests/NamingStrategyTest.php b/tests/NamingStrategyTest.php
index 5943207a89..157bb5f9d1 100644
--- a/tests/NamingStrategyTest.php
+++ b/tests/NamingStrategyTest.php
@@ -9,7 +9,6 @@
 
 class NamingStrategyTest extends TestCase
 {
-
     public function testGetInputTypeName(): void
     {
         $namingStrategy = new NamingStrategy();
@@ -43,4 +42,13 @@ public function testGetFieldNameFromTypeAnnotation(): void
         $name = $namingStrategy->getOutputTypeName(TestObject::class, $type);
         $this->assertSame('foo', $name);
     }
+
+    public function testGetUnionTypeName(): void
+    {
+        $namingStrategy = new NamingStrategy();
+
+        $typeNames = ['Some', 'Arbitrary', 'Type', 'Names'];
+        $name = $namingStrategy->getUnionTypeName($typeNames);
+        $this->assertSame('UnionSomeArbitraryTypeNames', $name);
+    }
 }
diff --git a/tests/Types/UnionTypeTest.php b/tests/Types/UnionTypeTest.php
index 580b45702a..122c326e57 100644
--- a/tests/Types/UnionTypeTest.php
+++ b/tests/Types/UnionTypeTest.php
@@ -8,12 +8,13 @@
 use TheCodingMachine\GraphQLite\AbstractQueryProviderTest;
 use TheCodingMachine\GraphQLite\Fixtures\TestObject;
 use TheCodingMachine\GraphQLite\Fixtures\TestObject2;
+use TheCodingMachine\GraphQLite\NamingStrategy;
 
 class UnionTypeTest extends AbstractQueryProviderTest
 {
     public function testConstructor(): void
     {
-        $unionType = new UnionType([$this->getTestObjectType(), $this->getTestObjectType2()], $this->getTypeMapper());
+        $unionType = new UnionType([$this->getTestObjectType(), $this->getTestObjectType2()], $this->getTypeMapper(), new NamingStrategy());
         $resolveInfo = $this->getMockBuilder(ResolveInfo::class)->disableOriginalConstructor()->getMock();
         $type = $unionType->resolveType(new TestObject('foo'), null, $resolveInfo);
         $this->assertSame($this->getTestObjectType(), $type);
@@ -23,7 +24,7 @@ public function testConstructor(): void
 
     public function testException(): void
     {
-        $unionType = new UnionType([$this->getTestObjectType(), $this->getTestObjectType2()], $this->getTypeMapper());
+        $unionType = new UnionType([$this->getTestObjectType(), $this->getTestObjectType2()], $this->getTypeMapper(), new NamingStrategy());
         $this->expectException(\InvalidArgumentException::class);
         $resolveInfo = $this->getMockBuilder(ResolveInfo::class)->disableOriginalConstructor()->getMock();
         $unionType->resolveType('foo', null, $resolveInfo);
@@ -32,6 +33,6 @@ public function testException(): void
     public function testException2(): void
     {
         $this->expectException(\InvalidArgumentException::class);
-        new UnionType([new StringType()], $this->getTypeMapper());
+        new UnionType([new StringType()], $this->getTypeMapper(), new NamingStrategy());
     }
 }