diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index d9af46cf..788d52a2 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -96,7 +96,7 @@ jobs:
             - run: composer require --no-update oneup/flysystem-bundle:"^4.0.1"
               if: matrix.with_oneupbundle
             - name: Update project dependencies
-              uses: ramsey/composer-install@v1
+              uses: ramsey/composer-install@v2
               with:
                 dependency-versions: ${{ matrix.dependencies }}
             - name: Run tests
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 3cfd35ce..34b45f84 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -104,7 +104,7 @@ private function addMappingsSection(ArrayNodeDefinition $node): void
                             ->scalarNode('uri_prefix')->defaultValue('/uploads')->end()
                             ->scalarNode('upload_destination')->isRequired()->end()
                             ->arrayNode('namer')
-                                ->addDefaultsIfNotSet()
+                                ->isRequired()
                                 ->beforeNormalization()
                                     ->ifString()
                                     ->then(static fn ($v) => ['service' => $v, 'options' => []])
diff --git a/tests/DependencyInjection/VichUploaderExtensionTest.php b/tests/DependencyInjection/VichUploaderExtensionTest.php
index fa9e9b6e..bdac3f3d 100644
--- a/tests/DependencyInjection/VichUploaderExtensionTest.php
+++ b/tests/DependencyInjection/VichUploaderExtensionTest.php
@@ -44,7 +44,7 @@ public function testStorageServiceParameterIsSet(): void
             'storage' => 'gaufrette',
         ]);
 
-        self::assertContainerBuilderHasAlias('vich_uploader.storage', 'vich_uploader.storage.gaufrette');
+        $this->assertContainerBuilderHasAlias('vich_uploader.storage', 'vich_uploader.storage.gaufrette');
     }
 
     public function testStorageServiceCustom(): void
@@ -53,7 +53,7 @@ public function testStorageServiceCustom(): void
             'storage' => '@acme.storage',
         ]);
 
-        self::assertContainerBuilderHasAlias('vich_uploader.storage', 'acme.storage');
+        $this->assertContainerBuilderHasAlias('vich_uploader.storage', 'acme.storage');
     }
 
     public function testExtraServiceFilesAreLoaded(): void
@@ -63,8 +63,8 @@ public function testExtraServiceFilesAreLoaded(): void
             'storage' => 'flysystem',
         ]);
 
-        self::assertContainerBuilderHasService('vich_uploader.storage.flysystem', FlysystemStorage::class);
-        self::assertContainerBuilderHasService(UploaderExtension::class);
+        $this->assertContainerBuilderHasService('vich_uploader.storage.flysystem', FlysystemStorage::class);
+        $this->assertContainerBuilderHasService(UploaderExtension::class);
     }
 
     public function testMappingsServiceParameterIsSet(): void
@@ -86,7 +86,7 @@ public function testMappingsServiceParameterIsSet(): void
         // the default db_driver is copied into the mapping
         $mappings['foo']['db_driver'] = 'orm';
 
-        self::assertContainerBuilderHasParameter('vich_uploader.mappings', $mappings);
+        $this->assertContainerBuilderHasParameter('vich_uploader.mappings', $mappings);
     }
 
     public function testDbDriverIsNotOverridden(): void
@@ -107,7 +107,7 @@ public function testDbDriverIsNotOverridden(): void
             ],
         ]);
 
-        self::assertContainerBuilderHasParameter('vich_uploader.mappings', $mappings);
+        $this->assertContainerBuilderHasParameter('vich_uploader.mappings', $mappings);
     }
 
     public function testListenersCreation(): void
@@ -127,9 +127,9 @@ public function testListenersCreation(): void
             ],
         ]);
 
-        self::assertContainerBuilderHasService('vich_uploader.listener.inject.profile_common_avatar');
-        self::assertContainerBuilderNotHasService('vich_uploader.listener.clean.profile_common_avatar');
-        self::assertContainerBuilderHasService('vich_uploader.listener.remove.profile_common_avatar');
+        $this->assertContainerBuilderHasService('vich_uploader.listener.inject.profile_common_avatar');
+        $this->assertContainerBuilderNotHasService('vich_uploader.listener.clean.profile_common_avatar');
+        $this->assertContainerBuilderHasService('vich_uploader.listener.remove.profile_common_avatar');
     }
 
     public function testFormThemeCorrectlyOverridden(): void
@@ -147,7 +147,7 @@ public function testFormThemeCorrectlyOverridden(): void
         ]], $this->container);
         $vichUploaderExtension->load([$this->getMinimalConfiguration()], $this->container);
 
-        self::assertContainerBuilderHasParameter(
+        $this->assertContainerBuilderHasParameter(
             'twig.form.resources',
             ['@VichUploader/Form/fields.html.twig', 'form_div_layout.html.twig', '@Ololo/trololo.html.twig']
         );
diff --git a/tests/Kernel/FlysystemOfficialAppKernel.php b/tests/Kernel/FlysystemOfficialAppKernel.php
index 4a2de4df..0f2163d3 100644
--- a/tests/Kernel/FlysystemOfficialAppKernel.php
+++ b/tests/Kernel/FlysystemOfficialAppKernel.php
@@ -9,6 +9,7 @@
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\HttpKernel\Kernel;
 use Vich\UploaderBundle\VichUploaderBundle;
+use Vich\UploaderBundle\Naming\UniqidNamer;
 
 /**
  * @author Titouan Galopin <galopintitouan@gmail.com>
@@ -56,6 +57,7 @@ public function registerContainerConfiguration(LoaderInterface $loader): void
                     'product_image' => [
                         'uri_prefix' => '/images/products',
                         'upload_destination' => 'uploads.storage',
+                        'namer' => UniqidNamer::class,
                     ],
                 ],
             ]);
diff --git a/tests/Kernel/FlysystemOneUpAppKernel.php b/tests/Kernel/FlysystemOneUpAppKernel.php
index 62101244..db4b9dd3 100644
--- a/tests/Kernel/FlysystemOneUpAppKernel.php
+++ b/tests/Kernel/FlysystemOneUpAppKernel.php
@@ -8,6 +8,7 @@
 use Symfony\Component\Config\Loader\LoaderInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\HttpKernel\Kernel;
+use Vich\UploaderBundle\Naming\UniqidNamer;
 use Vich\UploaderBundle\VichUploaderBundle;
 
 /**
@@ -61,6 +62,7 @@ public function registerContainerConfiguration(LoaderInterface $loader): void
                     'product_image' => [
                         'uri_prefix' => '/images/products',
                         'upload_destination' => 'oneup_flysystem.product_image_fs',
+                        'namer' => UniqidNamer::class,
                     ],
                 ],
             ]);