diff --git a/src/Mappers/RecursiveTypeMapper.php b/src/Mappers/RecursiveTypeMapper.php
index 0b3415740f..f55c341419 100644
--- a/src/Mappers/RecursiveTypeMapper.php
+++ b/src/Mappers/RecursiveTypeMapper.php
@@ -521,6 +521,6 @@ public function mapNameToType(string $typeName): Type&NamedType
             return $this->mapClassToInterfaceOrType($className, null);
         }
 
-        throw CannotMapTypeException::createForName($typeName);
+        throw TypeNotFoundException::createError($typeName);
     }
 }
diff --git a/src/Mappers/TypeNotFoundException.php b/src/Mappers/TypeNotFoundException.php
new file mode 100644
index 0000000000..2f5df7d0bf
--- /dev/null
+++ b/src/Mappers/TypeNotFoundException.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace TheCodingMachine\GraphQLite\Mappers;
+
+use GraphQL\Error\Error;
+use GraphQL\Utils\Utils;
+
+/**
+ * TypeNotFoundException thrown when RecursiveTypeMapper fails to find a type.
+ *
+ * While CannotMapTypeException is more about error with configuration this exception can occur when request
+ * contains a type which is unknown to the server.
+ * Should not be handled by the user, webonyx/graphql-php will transform this under 'errors' key in the response.
+ */
+class TypeNotFoundException extends Error
+{
+    public static function createError(string $typeName): Error
+    {
+        return static::createLocatedError('Unknown type ' . Utils::printSafe($typeName));
+    }
+}
diff --git a/tests/Mappers/RecursiveTypeMapperTest.php b/tests/Mappers/RecursiveTypeMapperTest.php
index cf474a64d8..7cba67ae9d 100644
--- a/tests/Mappers/RecursiveTypeMapperTest.php
+++ b/tests/Mappers/RecursiveTypeMapperTest.php
@@ -93,7 +93,7 @@ public function testMapNameToType2(): void
         $this->assertSame('ClassA', $recursiveMapper->mapNameToType('ClassA')->name);
         $this->assertSame('ClassAInterface', $recursiveMapper->mapNameToType('ClassAInterface')->name);
 
-        $this->expectException(CannotMapTypeException::class);
+        $this->expectException(TypeNotFoundException::class);
         $recursiveMapper->mapNameToType('NotExists');
     }
 
@@ -233,6 +233,8 @@ public function testDuplicateDetection(): void
 
     /**
      * Tests that the RecursiveTypeMapper behaves correctly if there are no types to map.
+     *
+     * @see \GraphQL\Server\Helper::promiseToExecuteOperation()
      */
     public function testMapNoTypes(): void
     {
@@ -244,7 +246,7 @@ public function testMapNoTypes(): void
             $this->getAnnotationReader()
         );
 
-        $this->expectException(CannotMapTypeException::class);
+        $this->expectException(TypeNotFoundException::class);
         $recursiveTypeMapper->mapNameToType('Foo');
     }
 
diff --git a/tests/SchemaFactoryTest.php b/tests/SchemaFactoryTest.php
index 090f8d91fd..908f265f57 100644
--- a/tests/SchemaFactoryTest.php
+++ b/tests/SchemaFactoryTest.php
@@ -1,8 +1,12 @@
 <?php
 
+declare(strict_types=1);
+
 namespace TheCodingMachine\GraphQLite;
 
+use Doctrine\Common\Annotations\AnnotationReader;
 use GraphQL\Error\DebugFlag;
+use GraphQL\Executor\ExecutionResult;
 use GraphQL\GraphQL;
 use GraphQL\Type\SchemaConfig;
 use Mouf\Composer\ClassNameMapper;
@@ -20,22 +24,19 @@
 use TheCodingMachine\GraphQLite\Fixtures\Integration\Types\ContactOtherType;
 use TheCodingMachine\GraphQLite\Fixtures\Integration\Types\ContactType;
 use TheCodingMachine\GraphQLite\Fixtures\Integration\Types\ExtendedContactType;
-use TheCodingMachine\GraphQLite\Mappers\CannotMapTypeException;
+use TheCodingMachine\GraphQLite\Fixtures\TestSelfType;
 use TheCodingMachine\GraphQLite\Mappers\CompositeTypeMapper;
 use TheCodingMachine\GraphQLite\Mappers\DuplicateMappingException;
+use TheCodingMachine\GraphQLite\Mappers\Parameters\ParameterMiddlewarePipe;
 use TheCodingMachine\GraphQLite\Mappers\Root\VoidRootTypeMapperFactory;
 use TheCodingMachine\GraphQLite\Mappers\StaticClassListTypeMapperFactory;
 use TheCodingMachine\GraphQLite\Middlewares\FieldMiddlewarePipe;
-use TheCodingMachine\GraphQLite\Mappers\Parameters\ParameterMiddlewarePipe;
 use TheCodingMachine\GraphQLite\Middlewares\InputFieldMiddlewarePipe;
 use TheCodingMachine\GraphQLite\Security\VoidAuthenticationService;
 use TheCodingMachine\GraphQLite\Security\VoidAuthorizationService;
-use TheCodingMachine\GraphQLite\Fixtures\TestSelfType;
-
 
 class SchemaFactoryTest extends TestCase
 {
-
     public function testCreateSchema(): void
     {
         $container = new BasicAutoWiringContainer(new EmptyContainer());
@@ -65,7 +66,7 @@ public function testSetters(): void
 
         $factory->addControllerNamespace('TheCodingMachine\\GraphQLite\\Fixtures\\Integration\\Controllers');
         $factory->addTypeNamespace('TheCodingMachine\\GraphQLite\\Fixtures\\Integration');
-        $factory->setDoctrineAnnotationReader(new \Doctrine\Common\Annotations\AnnotationReader())
+        $factory->setDoctrineAnnotationReader(new AnnotationReader())
                 ->setAuthenticationService(new VoidAuthenticationService())
                 ->setAuthorizationService(new VoidAuthorizationService())
                 ->setNamingStrategy(new NamingStrategy())
@@ -89,8 +90,8 @@ public function testClassNameMapperInjectionWithValidMapper(): void
         $factory = new SchemaFactory(
             new Psr16Cache(new ArrayAdapter()),
             new BasicAutoWiringContainer(
-                new EmptyContainer()
-            )
+                new EmptyContainer(),
+            ),
         );
         $factory->setAuthenticationService(new VoidAuthenticationService())
                 ->setAuthorizationService(new VoidAuthorizationService())
@@ -132,8 +133,8 @@ public function testClassNameMapperInjectionWithInvalidMapper(): void
         $factory = new SchemaFactory(
             new Psr16Cache(new ArrayAdapter()),
             new BasicAutoWiringContainer(
-                new EmptyContainer()
-            )
+                new EmptyContainer(),
+            ),
         );
         $factory->setAuthenticationService(new VoidAuthenticationService())
                 ->setAuthorizationService(new VoidAuthorizationService())
@@ -141,8 +142,7 @@ public function testClassNameMapperInjectionWithInvalidMapper(): void
                 ->addControllerNamespace('TheCodingMachine\\GraphQLite\\Fixtures\\Integration\\Controllers')
                 ->addTypeNamespace('TheCodingMachine\\GraphQLite\\Fixtures\\Integration');
 
-        $this->expectException(CannotMapTypeException::class);
-        $this->doTestSchema($factory->createSchema());
+        $this->doTestSchemaWithError($factory->createSchema());
     }
 
     public function testException(): void
@@ -168,9 +168,8 @@ public function testException2(): void
         $factory->createSchema();
     }
 
-    private function doTestSchema(Schema $schema): void
+    private function execTestQuery(Schema $schema): ExecutionResult
     {
-
         $schema->assertValid();
 
         $queryString = '
@@ -185,25 +184,41 @@ private function doTestSchema(Schema $schema): void
         }
         ';
 
-        $result = GraphQL::executeQuery(
+        return GraphQL::executeQuery(
             $schema,
-            $queryString
+            $queryString,
         );
+    }
+
+    private function doTestSchemaWithError(Schema $schema): void
+    {
+        $result = $this->execTestQuery($schema);
+        $resultArr = $result->toArray(DebugFlag::RETHROW_INTERNAL_EXCEPTIONS);
+        $this->assertArrayHasKey('errors', $resultArr);
+        $this->assertArrayNotHasKey('data', $resultArr);
+        $this->assertCount(1, $resultArr);
+        $this->assertSame('Unknown type "User"', $resultArr['errors'][0]['message']);
+    }
 
+    private function doTestSchema(Schema $schema): void
+    {
+        $result = $this->execTestQuery($schema);
+        $resultArr = $result->toArray(DebugFlag::RETHROW_INTERNAL_EXCEPTIONS);
+        $this->assertArrayHasKey('data', $resultArr);
         $this->assertSame([
             'contacts' => [
                 [
                     'name' => 'Joe',
-                    'uppercaseName' => 'JOE'
+                    'uppercaseName' => 'JOE',
                 ],
                 [
                     'name' => 'Bill',
                     'uppercaseName' => 'BILL',
-                    'email' => 'bill@example.com'
-                ]
+                    'email' => 'bill@example.com',
+                ],
 
-            ]
-        ], $result->toArray(DebugFlag::RETHROW_INTERNAL_EXCEPTIONS)['data']);
+            ],
+        ], $resultArr['data']);
     }
 
     public function testDuplicateQueryException(): void
@@ -211,8 +226,8 @@ public function testDuplicateQueryException(): void
         $factory = new SchemaFactory(
             new Psr16Cache(new ArrayAdapter()),
             new BasicAutoWiringContainer(
-                new EmptyContainer()
-            )
+                new EmptyContainer(),
+            ),
         );
         $factory->setAuthenticationService(new VoidAuthenticationService())
                 ->setAuthorizationService(new VoidAuthorizationService())
@@ -229,7 +244,7 @@ public function testDuplicateQueryException(): void
         ';
         GraphQL::executeQuery(
             $schema,
-            $queryString
+            $queryString,
         );
     }
 
@@ -238,8 +253,8 @@ public function testDuplicateQueryInTwoControllersException(): void
         $factory = new SchemaFactory(
             new Psr16Cache(new ArrayAdapter()),
             new BasicAutoWiringContainer(
-                new EmptyContainer()
-            )
+                new EmptyContainer(),
+            ),
         );
         $factory->setAuthenticationService(new VoidAuthenticationService())
             ->setAuthorizationService(new VoidAuthorizationService())
@@ -256,7 +271,7 @@ public function testDuplicateQueryInTwoControllersException(): void
         ';
         GraphQL::executeQuery(
             $schema,
-            $queryString
+            $queryString,
         );
     }
 }