diff --git a/src/Doctrine/DoctrineMetadataFactory.php b/src/Doctrine/DoctrineMetadataFactory.php
index b5a616539..d1b7e067e 100644
--- a/src/Doctrine/DoctrineMetadataFactory.php
+++ b/src/Doctrine/DoctrineMetadataFactory.php
@@ -12,6 +12,9 @@
 namespace Symfony\Bundle\MakerBundle\Doctrine;
 
 use Doctrine\Common\Persistence\ManagerRegistry;
+use Doctrine\Common\Persistence\Mapping\Driver\MappingDriver;
+use Doctrine\Common\Persistence\Mapping\Driver\MappingDriverChain;
+use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\Mapping\ClassMetadata;
 use Doctrine\ORM\Tools\DisconnectedClassMetadataFactory;
 
@@ -69,6 +72,30 @@ public function getMetadataForClass(string $entity): ?ClassMetadata
         return null;
     }
 
+    public function getMappingDriverForClass(string $className): ?MappingDriver
+    {
+        /** @var EntityManagerInterface $em */
+        $em = $this->registry->getManagerForClass($className);
+
+        if (null === $em) {
+            throw new \InvalidArgumentException(sprintf('Cannot find the entity manager for class "%s"', $className));
+        }
+
+        $metadataDriver = $em->getConfiguration()->getMetadataDriverImpl();
+
+        if (!$metadataDriver instanceof MappingDriverChain) {
+            return $metadataDriver;
+        }
+
+        foreach ($metadataDriver->getDrivers() as $namespace => $driver) {
+            if (0 === strpos($className, $namespace)) {
+                return $driver;
+            }
+        }
+
+        return $metadataDriver->getDefaultDriver();
+    }
+
     /**
      * @return array
      */
diff --git a/src/Maker/MakeEntity.php b/src/Maker/MakeEntity.php
index b7e252770..76ff2f779 100644
--- a/src/Maker/MakeEntity.php
+++ b/src/Maker/MakeEntity.php
@@ -15,8 +15,11 @@
 use Doctrine\Common\Persistence\ManagerRegistry;
 use Doctrine\DBAL\Types\Type;
 use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Driver\AnnotationDriver;
 use Symfony\Bundle\MakerBundle\ConsoleStyle;
 use Symfony\Bundle\MakerBundle\DependencyBuilder;
+use Symfony\Bundle\MakerBundle\Doctrine\DoctrineMetadataFactory;
+use Symfony\Bundle\MakerBundle\Exception\RuntimeCommandException;
 use Symfony\Bundle\MakerBundle\Generator;
 use Symfony\Bundle\MakerBundle\InputConfiguration;
 use Symfony\Bundle\MakerBundle\Str;
@@ -122,7 +125,8 @@ public function generate(InputInterface $input, ConsoleStyle $io, Generator $gen
             'Repository'
         );
 
-        if (!class_exists($entityClassDetails->getFullName())) {
+        $classExists = class_exists($entityClassDetails->getFullName());
+        if (!$classExists) {
             $entityPath = $generator->generateClass(
                 $entityClassDetails->getFullName(),
                 'doctrine/Entity.tpl.php',
@@ -143,21 +147,26 @@ public function generate(InputInterface $input, ConsoleStyle $io, Generator $gen
             );
 
             $generator->writeChanges();
+        }
+
+        if (!$this->doesEntityUseAnnotationMapping($entityClassDetails->getFullName())) {
+            throw new RuntimeCommandException(sprintf('Only annotation mapping is supported by make:entity, but the <info>%s</info> class uses a different format. If you would like this command to generate the properties & getter/setter methods, add your mapping configuration, and then re-run this command with the <info>--regenerate</info> flag.', $entityClassDetails->getFullName()));
+        }
 
+        if ($classExists) {
+            $entityPath = $this->getPathOfClass($entityClassDetails->getFullName());
             $io->text([
-                '',
-                'Entity generated! Now let\'s add some fields!',
-                'You can always add more fields later manually or by re-running this command.',
+                'Your entity already exists! So let\'s add some new fields!',
             ]);
         } else {
-            $entityPath = $this->getPathOfClass($entityClassDetails->getFullName());
             $io->text([
-                'Your entity already exists! So let\'s add some new fields!',
+                '',
+                'Entity generated! Now let\'s add some fields!',
+                'You can always add more fields later manually or by re-running this command.',
             ]);
         }
 
         $currentFields = $this->getPropertyNames($entityClassDetails->getFullName());
-
         $manipulator = $this->createClassManipulator($entityPath, $io, $overwrite);
 
         $isFirstField = true;
@@ -782,4 +791,23 @@ private function getPropertyNames(string $class): array
             return $prop->getName();
         }, $reflClass->getProperties());
     }
+
+    private function doesEntityUseAnnotationMapping(string $className): bool
+    {
+        $metadataFactory = new DoctrineMetadataFactory($this->registry);
+        if (!class_exists($className)) {
+            $otherClassMetadatas = $metadataFactory->getMetadataForNamespace(Str::getNamespace($className));
+
+            // if we have no metadata, we should assume this is the first class being mapped
+            if (empty($otherClassMetadatas)) {
+                return false;
+            }
+
+            $className = $otherClassMetadatas[0]->name;
+        }
+
+        $metadataFactory->getMappingDriverForClass($className);
+
+        return $metadataFactory instanceof AnnotationDriver;
+    }
 }
diff --git a/src/Test/MakerTestCase.php b/src/Test/MakerTestCase.php
index fdef87019..c51a7a35c 100644
--- a/src/Test/MakerTestCase.php
+++ b/src/Test/MakerTestCase.php
@@ -93,7 +93,7 @@ protected function executeMakerCommand(MakerTestDetails $testDetails)
 
         $makerProcess->run();
 
-        if (!$makerProcess->isSuccessful()) {
+        if (!$makerProcess->isSuccessful() && !$testDetails->isCommandAllowedToFail()) {
             throw new \Exception(sprintf('Running maker command failed: "%s" "%s"', $makerProcess->getOutput(), $makerProcess->getErrorOutput()));
         }
 
diff --git a/src/Test/MakerTestDetails.php b/src/Test/MakerTestDetails.php
index 6c8a84200..241517de7 100644
--- a/src/Test/MakerTestDetails.php
+++ b/src/Test/MakerTestDetails.php
@@ -34,6 +34,8 @@ final class MakerTestDetails
 
     private $argumentsString = '';
 
+    private $commandAllowedToFail = false;
+
     /**
      * @param MakerInterface $maker
      * @param array          $inputs
@@ -153,6 +155,13 @@ public function setArgumentsString(string $argumentsString): self
         return $this;
     }
 
+    public function setCommandAllowedToFail(bool $commandAllowedToFail): self
+    {
+        $this->commandAllowedToFail = $commandAllowedToFail;
+
+        return $this;
+    }
+
     public function getInputs(): array
     {
         return $this->inputs;
@@ -216,4 +225,9 @@ public function getArgumentsString(): string
     {
         return $this->argumentsString;
     }
+
+    public function isCommandAllowedToFail(): bool
+    {
+        return $this->commandAllowedToFail;
+    }
 }
diff --git a/tests/Maker/FunctionalTest.php b/tests/Maker/FunctionalTest.php
index 1fa99f467..8d79e76c2 100644
--- a/tests/Maker/FunctionalTest.php
+++ b/tests/Maker/FunctionalTest.php
@@ -191,7 +191,7 @@ public function getCommandTests()
             ->updateSchemaAfterCommand()
         ];
 
-        yield 'entity_many_to_one_simple' => [MakerTestDetails::createTest(
+        yield 'entity_many_to_one_simple_with_inverse' => [MakerTestDetails::createTest(
             $this->getMakerInstance(MakeEntity::class),
             [
                 // entity class name
@@ -476,6 +476,52 @@ public function getCommandTests()
             ->configureDatabase(false)
         ];
 
+        yield 'entity_xml_mapping_error_existing' => [MakerTestDetails::createTest(
+            $this->getMakerInstance(MakeEntity::class),
+            [
+                'User',
+            ])
+            ->setFixtureFilesPath(__DIR__ . '/../fixtures/MakeEntityXmlMappingError')
+            ->addReplacement(
+                'config/packages/doctrine.yaml',
+                'type: annotation',
+                'type: xml'
+            )
+            ->addReplacement(
+                'config/packages/doctrine.yaml',
+                "dir: '%kernel.project_dir%/src/Entity'",
+                "dir: '%kernel.project_dir%/config/doctrine'"
+            )
+            ->configureDatabase(false)
+            ->setCommandAllowedToFail(true)
+            ->assert(function(string $output, string $directory) {
+                $this->assertContains('Only annotation mapping is supported', $output);
+            })
+        ];
+
+        yield 'entity_xml_mapping_error_new_class' => [MakerTestDetails::createTest(
+            $this->getMakerInstance(MakeEntity::class),
+            [
+                'UserAvatarPhoto',
+            ])
+            ->setFixtureFilesPath(__DIR__ . '/../fixtures/MakeEntityXmlMappingError')
+            ->addReplacement(
+                'config/packages/doctrine.yaml',
+                'type: annotation',
+                'type: xml'
+            )
+            ->addReplacement(
+                'config/packages/doctrine.yaml',
+                "dir: '%kernel.project_dir%/src/Entity'",
+                "dir: '%kernel.project_dir%/config/doctrine'"
+            )
+            ->configureDatabase(false)
+            ->setCommandAllowedToFail(true)
+            ->assert(function(string $output, string $directory) {
+                $this->assertContains('Only annotation mapping is supported', $output);
+            })
+        ];
+
         yield 'entity_updating_overwrite' => [MakerTestDetails::createTest(
             $this->getMakerInstance(MakeEntity::class),
             [
diff --git a/tests/fixtures/MakeEntityXmlMappingError/config/doctrine/User.orm.xml b/tests/fixtures/MakeEntityXmlMappingError/config/doctrine/User.orm.xml
new file mode 100644
index 000000000..322344224
--- /dev/null
+++ b/tests/fixtures/MakeEntityXmlMappingError/config/doctrine/User.orm.xml
@@ -0,0 +1,12 @@
+<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping
+        http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd">
+
+    <entity name="App\Entity\User">
+        <id name="id" type="integer">
+            <generator strategy="AUTO" />
+        </id>
+        <one-to-many field="avatars" target-entity="UserAvatar" mapped-by="user" />
+    </entity>
+</doctrine-mapping>
\ No newline at end of file
diff --git a/tests/fixtures/MakeEntityXmlMappingError/src/Entity/User.php b/tests/fixtures/MakeEntityXmlMappingError/src/Entity/User.php
new file mode 100644
index 000000000..8c2e33ba5
--- /dev/null
+++ b/tests/fixtures/MakeEntityXmlMappingError/src/Entity/User.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace App\Entity;
+
+class User
+{
+    private $id;
+
+    public function getId(): ?int
+    {
+        // custom comment
+        return $this->id;
+    }
+
+    // add your own fields
+}