diff --git a/composer.json b/composer.json
index a8f304c..f802e96 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,7 @@
         "ext-simplexml": "*",
         "php-static-analysis/attributes": "^0.4.1 || dev-main",
         "php-static-analysis/node-visitor": "^0.4.1 || dev-main",
-        "vimeo/psalm": "^6",
+        "vimeo/psalm": "^6.12",
         "webmozart/assert": "^1.11"
     },
     "require-dev": {
diff --git a/patches/vimeo-psalm-src-psalm-internal-codebase-analizer-php.patch b/patches/vimeo-psalm-src-psalm-internal-codebase-analizer-php.patch
new file mode 100644
index 0000000..ce549a3
--- /dev/null
+++ b/patches/vimeo-psalm-src-psalm-internal-codebase-analizer-php.patch
@@ -0,0 +1,16 @@
+diff --git a/src/Psalm/Internal/Codebase/Analyzer.php b/src/Psalm/Internal/Codebase/Analyzer.php
+index f9127a517..41f94a174 100644
+--- a/src/Psalm/Internal/Codebase/Analyzer.php
++++ b/src/Psalm/Internal/Codebase/Analyzer.php
+@@ -812,7 +812,10 @@ final class Analyzer
+         );
+     }
+ 
+-    public function shiftFileOffsets(StatementsProvider $statements_provider): void
++    /**
++     * @param StatementsProvider $statements_provider
++     */
++    public function shiftFileOffsets($statements_provider): void
+     {
+         $diff_map = $statements_provider->getDiffMap();
+         $deletion_ranges = $statements_provider->getDeletionRanges();
diff --git a/patches/vimeo-psalm-src-psalm-internal-provider-parsercacheprovider-php.patch b/patches/vimeo-psalm-src-psalm-internal-provider-parsercacheprovider-php.patch
new file mode 100644
index 0000000..1b0c131
--- /dev/null
+++ b/patches/vimeo-psalm-src-psalm-internal-provider-parsercacheprovider-php.patch
@@ -0,0 +1,13 @@
+diff --git a/src/Psalm/Internal/Provider/ParserCacheProvider.php b/src/Psalm/Internal/Provider/ParserCacheProvider.php
+index f352519f2..c2351841e 100644
+--- a/src/Psalm/Internal/Provider/ParserCacheProvider.php
++++ b/src/Psalm/Internal/Provider/ParserCacheProvider.php
+@@ -13,7 +13,7 @@ use function filemtime;
+ use const DIRECTORY_SEPARATOR;
+ 
+ /** @internal */
+-final class ParserCacheProvider
++class ParserCacheProvider
+ {
+     private const PARSER_CACHE_DIRECTORY = 'php-parser';
+ 
diff --git a/patches/vimeo-psalm-tests-testconfig-php.patch b/patches/vimeo-psalm-tests-testconfig-php.patch
new file mode 100644
index 0000000..2166420
--- /dev/null
+++ b/patches/vimeo-psalm-tests-testconfig-php.patch
@@ -0,0 +1,13 @@
+diff --git a/tests/TestConfig.php b/tests/TestConfig.php
+index b5bac8fcc..970ac2b40 100644
+--- a/tests/TestConfig.php
++++ b/tests/TestConfig.php
+@@ -12,7 +12,7 @@ use SimpleXMLElement;
+ 
+ use function getcwd;
+ 
+-final class TestConfig extends Config
++class TestConfig extends Config
+ {
+     private static ?ProjectFileFilter $cached_project_files = null;
+ 
diff --git a/psalm.xml b/psalm.xml
index 92e584a..fb591f5 100644
--- a/psalm.xml
+++ b/psalm.xml
@@ -7,6 +7,7 @@
         errorLevel="1"
         findUnusedBaselineEntry="true"
         findUnusedCode="false"
+        ensureOverrideAttribute="false"
 >
     <projectFiles>
         <directory name="src" />
diff --git a/src/Composer/Plugin.php b/src/Composer/Plugin.php
index 9fe18e9..1a228d8 100644
--- a/src/Composer/Plugin.php
+++ b/src/Composer/Plugin.php
@@ -9,7 +9,7 @@
 use Composer\Script\Event;
 use PhpStaticAnalysis\Attributes\Returns;
 
-class Plugin implements PluginInterface, EventSubscriberInterface
+final class Plugin implements PluginInterface, EventSubscriberInterface
 {
     public function activate(Composer $composer, IOInterface $io)
     {
@@ -50,12 +50,25 @@ private static function applyPatches(Event $event): void
         $vendorDir = $event->getComposer()->getConfig()->get('vendor-dir');
 
         $dependencyPath = $vendorDir . '/vimeo/psalm';
-        $patchFile = __DIR__ . '/../../patches/vimeo-psalm-src-psalm-config-php.patch';
+        $patchesDir = __DIR__ . '/../../patches/';
+        $patchFiles = glob($patchesDir . '*.patch');
 
-        exec("patch -p1 -d $dependencyPath --forward < $patchFile");
+        if ($patchFiles === false) {
+            echo "No patches to apply\n";
+            return;
+        }
+        foreach ($patchFiles as $patchFile) {
+            $escapedPatchFile = escapeshellarg($patchFile);
+            $escapedDependencyPath = escapeshellarg($dependencyPath);
 
-        $patchFile = __DIR__ . '/../../patches/vimeo-psalm-src-psalm-codebase-php.patch';
+            $cmd = "patch -p1 -d $escapedDependencyPath --forward < $escapedPatchFile";
+            exec($cmd, $output, $returnVar);
 
-        exec("patch -p1 -d $dependencyPath --forward < $patchFile");
+            if ($returnVar !== 0) {
+                echo "Failed to apply patch: $patchFile\n";
+            } else {
+                echo "Applied patch: $patchFile\n";
+            }
+        }
     }
 }
diff --git a/src/Plugin.php b/src/Plugin.php
index 98d6997..61ebd9e 100644
--- a/src/Plugin.php
+++ b/src/Plugin.php
@@ -10,7 +10,7 @@
 use Psalm\Plugin\RegistrationInterface;
 use SimpleXMLElement;
 
-class Plugin implements PluginEntryPointInterface
+final class Plugin implements PluginEntryPointInterface
 {
     public function __invoke(RegistrationInterface $registration, ?SimpleXMLElement $config = null): void
     {
diff --git a/src/Provider/AttributeStatementProvider.php b/src/Provider/AttributeStatementProvider.php
index 14d0ad9..72ab888 100644
--- a/src/Provider/AttributeStatementProvider.php
+++ b/src/Provider/AttributeStatementProvider.php
@@ -14,7 +14,7 @@
 use Psalm\Progress\Progress;
 use Webmozart\Assert\Assert;
 
-class AttributeStatementProvider
+final class AttributeStatementProvider
 {
     private StatementsProvider $statementsProvider;
 
@@ -27,12 +27,14 @@ public function __construct(StatementsProvider $statementsProvider)
     public function getStatementsForFile(
         string $file_path,
         int $analysis_php_version_id,
+        bool $do_diff,
         ?Progress $progress = null
     ): array {
         /** @psalm-suppress InternalMethod */
         $ast = $this->statementsProvider->getStatementsForFile(
             $file_path,
             $analysis_php_version_id,
+            $do_diff,
             $progress
         );
         return $this->traverseAst($ast);
diff --git a/tests/AssertAttributeTest.php b/tests/AssertAttributeTest.php
index b66c653..d999ad8 100644
--- a/tests/AssertAttributeTest.php
+++ b/tests/AssertAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class AssertAttributeTest extends BaseAttributeTestCase
+final class AssertAttributeTest extends BaseAttributeTestCase
 {
     public function testFunctionAssertAttribute(): void
     {
diff --git a/tests/AssertIfFalseAttributeTest.php b/tests/AssertIfFalseAttributeTest.php
index a1c873f..f30d8d6 100644
--- a/tests/AssertIfFalseAttributeTest.php
+++ b/tests/AssertIfFalseAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class AssertIfFalseAttributeTest extends BaseAttributeTestCase
+final class AssertIfFalseAttributeTest extends BaseAttributeTestCase
 {
     public function testFunctionAssertIfFalseAttribute(): void
     {
diff --git a/tests/AssertIfTrueAttributeTest.php b/tests/AssertIfTrueAttributeTest.php
index 5a0e0ca..6fe720f 100644
--- a/tests/AssertIfTrueAttributeTest.php
+++ b/tests/AssertIfTrueAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class AssertIfTrueAttributeTest extends BaseAttributeTestCase
+final class AssertIfTrueAttributeTest extends BaseAttributeTestCase
 {
     public function testFunctionAssertIfTrueAttribute(): void
     {
diff --git a/tests/AttributeTestConfig.php b/tests/AttributeTestConfig.php
index f4cf439..247c3f9 100644
--- a/tests/AttributeTestConfig.php
+++ b/tests/AttributeTestConfig.php
@@ -8,7 +8,7 @@
 use Psalm\Progress\Progress;
 use Psalm\Tests\TestConfig;
 
-class AttributeTestConfig extends TestConfig
+final class AttributeTestConfig extends TestConfig
 {
     protected function getContents(): string
     {
diff --git a/tests/DefineTypeAttributeTest.php b/tests/DefineTypeAttributeTest.php
index 7bb3cb4..9c3a6a2 100644
--- a/tests/DefineTypeAttributeTest.php
+++ b/tests/DefineTypeAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class DefineTypeAttributeTest extends BaseAttributeTestCase
+final class DefineTypeAttributeTest extends BaseAttributeTestCase
 {
     public function testClassDefineTypeAttribute(): void
     {
diff --git a/tests/DeprecatedAttributeTest.php b/tests/DeprecatedAttributeTest.php
index f3bec7d..8a7c6bf 100644
--- a/tests/DeprecatedAttributeTest.php
+++ b/tests/DeprecatedAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class DeprecatedAttributeTest extends BaseAttributeTestCase
+final class DeprecatedAttributeTest extends BaseAttributeTestCase
 {
     public function testClassDeprecatedAttribute(): void
     {
diff --git a/tests/ImmutableAttributeTest.php b/tests/ImmutableAttributeTest.php
index f4c7714..3af7fd4 100644
--- a/tests/ImmutableAttributeTest.php
+++ b/tests/ImmutableAttributeTest.php
@@ -3,7 +3,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class ImmutableAttributeTest extends BaseAttributeTestCase
+final class ImmutableAttributeTest extends BaseAttributeTestCase
 {
     public function testClassImmutableAttribute(): void
     {
diff --git a/tests/ImportTypeAttributeTest.php b/tests/ImportTypeAttributeTest.php
index 2f9dd06..50687c4 100644
--- a/tests/ImportTypeAttributeTest.php
+++ b/tests/ImportTypeAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class ImportTypeAttributeTest extends BaseAttributeTestCase
+final class ImportTypeAttributeTest extends BaseAttributeTestCase
 {
     public function testClassImportTypeAttribute(): void
     {
diff --git a/tests/InternalAttributeTest.php b/tests/InternalAttributeTest.php
index 6891912..5ff614a 100644
--- a/tests/InternalAttributeTest.php
+++ b/tests/InternalAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class InternalAttributeTest extends BaseAttributeTestCase
+final class InternalAttributeTest extends BaseAttributeTestCase
 {
     public function testClassInternalAttribute(): void
     {
diff --git a/tests/IsReadOnlyAttributeTest.php b/tests/IsReadOnlyAttributeTest.php
index ccc12ac..c6e20c2 100644
--- a/tests/IsReadOnlyAttributeTest.php
+++ b/tests/IsReadOnlyAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class IsReadOnlyAttributeTest extends BaseAttributeTestCase
+final class IsReadOnlyAttributeTest extends BaseAttributeTestCase
 {
     public function testPropertyIsReadOnlyAttribute(): void
     {
diff --git a/tests/MethodAttributeTest.php b/tests/MethodAttributeTest.php
index 46b75d1..d10b1a1 100644
--- a/tests/MethodAttributeTest.php
+++ b/tests/MethodAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class MethodAttributeTest extends BaseAttributeTestCase
+final class MethodAttributeTest extends BaseAttributeTestCase
 {
     public function testClassMethodAttribute(): void
     {
@@ -27,6 +27,7 @@ public function testInvalidClassMethodAttribute(): void
         $errors = $this->analyzeTestFile( '/data/Method/InvalidClassMethodAttribute.php');
 
         $expectedErrors = [
+            'Magic method test\PhpStaticAnalysis\PsalmPlugin\data\Method\InvalidClassMethodAttribute::badfunction does not exist' => 34,
             'No @method entry specified in docblock for test\PhpStaticAnalysis\PsalmPlugin\data\Method\InvalidClassMethodAttribute' => 9,
             'Attribute Method cannot be used on a method' => 11,
             'string is not a valid method in docblock for test\PhpStaticAnalysis\PsalmPlugin\data\Method\AnotherInvalidClassMethodAttribute' => 29,
diff --git a/tests/MixinAttributeTest.php b/tests/MixinAttributeTest.php
index 89f0ad2..a089ee0 100644
--- a/tests/MixinAttributeTest.php
+++ b/tests/MixinAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class MixinAttributeTest extends BaseAttributeTestCase
+final class MixinAttributeTest extends BaseAttributeTestCase
 {
     public function testClassMixinAttribute(): void
     {
diff --git a/tests/ParamAttributeTest.php b/tests/ParamAttributeTest.php
index ad0d6d2..0aace27 100644
--- a/tests/ParamAttributeTest.php
+++ b/tests/ParamAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class ParamAttributeTest extends BaseAttributeTestCase
+final class ParamAttributeTest extends BaseAttributeTestCase
 {
     public function testFunctionParamAttribute(): void
     {
diff --git a/tests/ParamOutAttributeTest.php b/tests/ParamOutAttributeTest.php
index 24243b0..b64a4a1 100644
--- a/tests/ParamOutAttributeTest.php
+++ b/tests/ParamOutAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class ParamOutAttributeTest extends BaseAttributeTestCase
+final class ParamOutAttributeTest extends BaseAttributeTestCase
 {
     public function testMethodParamOutAttribute(): void
     {
diff --git a/tests/PropertyAttributeTest.php b/tests/PropertyAttributeTest.php
index e6319df..0e8b844 100644
--- a/tests/PropertyAttributeTest.php
+++ b/tests/PropertyAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class PropertyAttributeTest extends BaseAttributeTestCase
+final class PropertyAttributeTest extends BaseAttributeTestCase
 {
     public function testClassPropertyAttribute(): void
     {
diff --git a/tests/PropertyReadAttributeTest.php b/tests/PropertyReadAttributeTest.php
index 229bdc2..ea40bd1 100644
--- a/tests/PropertyReadAttributeTest.php
+++ b/tests/PropertyReadAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class PropertyReadAttributeTest extends BaseAttributeTestCase
+final class PropertyReadAttributeTest extends BaseAttributeTestCase
 {
     public function testClassPropertyReadAttribute(): void
     {
@@ -27,6 +27,7 @@ public function testInvalidClassPropertyReadAttribute(): void
         $errors = $this->analyzeTestFile('/data/PropertyRead/InvalidClassPropertyReadAttribute.php');
 
         $expectedErrors = [
+            'Magic instance property test\PhpStaticAnalysis\PsalmPlugin\data\PropertyRead\InvalidClassPropertyReadAttribute::$name is not defined' => 39,
             'Badly-formatted @property in docblock for test\PhpStaticAnalysis\PsalmPlugin\data\PropertyRead\InvalidClassPropertyReadAttribute' => 9,
             'Attribute PropertyRead cannot be used on a method' => 11,
             'Badly-formatted @property in docblock for test\PhpStaticAnalysis\PsalmPlugin\data\PropertyRead\AnotherInvalidClassPropertyReadAttribute' => 29,
diff --git a/tests/PropertyWriteAttributeTest.php b/tests/PropertyWriteAttributeTest.php
index 7ff00fd..cf367d1 100644
--- a/tests/PropertyWriteAttributeTest.php
+++ b/tests/PropertyWriteAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class PropertyWriteAttributeTest extends BaseAttributeTestCase
+final class PropertyWriteAttributeTest extends BaseAttributeTestCase
 {
     public function testClassPropertyWriteAttribute(): void
     {
@@ -27,6 +27,7 @@ public function testInvalidClassPropertyWriteAttribute(): void
         $errors = $this->analyzeTestFile('/data/PropertyWrite/InvalidClassPropertyWriteAttribute.php');
 
         $expectedErrors = [
+            'Magic instance property test\PhpStaticAnalysis\PsalmPlugin\data\PropertyWrite\InvalidClassPropertyWriteAttribute::$name is not defined' => 39,
             'Unable to determine the type that $foo is being assigned to' => 39,
             'Badly-formatted @property in docblock for test\PhpStaticAnalysis\PsalmPlugin\data\PropertyWrite\InvalidClassPropertyWriteAttribute' => 9,
             'Attribute PropertyWrite cannot be used on a method' => 11,
diff --git a/tests/PureAttributeTest.php b/tests/PureAttributeTest.php
index 45935d9..0ea6513 100644
--- a/tests/PureAttributeTest.php
+++ b/tests/PureAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class PureAttributeTest extends BaseAttributeTestCase
+final class PureAttributeTest extends BaseAttributeTestCase
 {
     public function testMethodPureAttribute(): void
     {
diff --git a/tests/RequireExtendsAttributeTest.php b/tests/RequireExtendsAttributeTest.php
index 174c651..9598d3b 100644
--- a/tests/RequireExtendsAttributeTest.php
+++ b/tests/RequireExtendsAttributeTest.php
@@ -3,7 +3,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class RequireExtendsAttributeTest extends BaseAttributeTestCase
+final class RequireExtendsAttributeTest extends BaseAttributeTestCase
 {
     public function testClassRequireExtendsAttribute(): void
     {
diff --git a/tests/RequireImplementsAttributeTest.php b/tests/RequireImplementsAttributeTest.php
index d752399..efbed08 100644
--- a/tests/RequireImplementsAttributeTest.php
+++ b/tests/RequireImplementsAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class RequireImplementsAttributeTest extends BaseAttributeTestCase
+final class RequireImplementsAttributeTest extends BaseAttributeTestCase
 {
     public function testClassRequireImplementsAttribute(): void
     {
diff --git a/tests/ReturnsAttributeTest.php b/tests/ReturnsAttributeTest.php
index 7c1bd0c..05e6339 100644
--- a/tests/ReturnsAttributeTest.php
+++ b/tests/ReturnsAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class ReturnsAttributeTest extends BaseAttributeTestCase
+final class ReturnsAttributeTest extends BaseAttributeTestCase
 {
     public function testFunctionReturnsAttribute(): void
     {
diff --git a/tests/SelfOutAttributeTest.php b/tests/SelfOutAttributeTest.php
index 84148d3..4ddabae 100644
--- a/tests/SelfOutAttributeTest.php
+++ b/tests/SelfOutAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class SelfOutAttributeTest extends BaseAttributeTestCase
+final class SelfOutAttributeTest extends BaseAttributeTestCase
 {
     public function testMethodSelfOutAttribute(): void
     {
diff --git a/tests/TemplateAttributeTest.php b/tests/TemplateAttributeTest.php
index 8c0765f..4b40daf 100644
--- a/tests/TemplateAttributeTest.php
+++ b/tests/TemplateAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class TemplateAttributeTest extends BaseAttributeTestCase
+final class TemplateAttributeTest extends BaseAttributeTestCase
 {
     public function testFunctionTemplateAttribute(): void
     {
diff --git a/tests/TemplateCovariantAttributeTest.php b/tests/TemplateCovariantAttributeTest.php
index ab91a51..f49cb6c 100644
--- a/tests/TemplateCovariantAttributeTest.php
+++ b/tests/TemplateCovariantAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class TemplateCovariantAttributeTest extends BaseAttributeTestCase
+final class TemplateCovariantAttributeTest extends BaseAttributeTestCase
 {
     public function testClassTemplateCovariantAttribute(): void
     {
diff --git a/tests/TemplateExtendsAttributeTest.php b/tests/TemplateExtendsAttributeTest.php
index 41ac3eb..985aeca 100644
--- a/tests/TemplateExtendsAttributeTest.php
+++ b/tests/TemplateExtendsAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class TemplateExtendsAttributeTest extends BaseAttributeTestCase
+final class TemplateExtendsAttributeTest extends BaseAttributeTestCase
 {
     public function testClassTemplateExtendsAttribute(): void
     {
diff --git a/tests/TemplateImplementsAttributeTest.php b/tests/TemplateImplementsAttributeTest.php
index bae65f3..aabd475 100644
--- a/tests/TemplateImplementsAttributeTest.php
+++ b/tests/TemplateImplementsAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class TemplateImplementsAttributeTest extends BaseAttributeTestCase
+final class TemplateImplementsAttributeTest extends BaseAttributeTestCase
 {
     public function testInterfaceTemplateImplementsAttribute(): void
     {
diff --git a/tests/TemplateUseAttributeTest.php b/tests/TemplateUseAttributeTest.php
index 4f36b99..529c059 100644
--- a/tests/TemplateUseAttributeTest.php
+++ b/tests/TemplateUseAttributeTest.php
@@ -2,7 +2,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class TemplateUseAttributeTest extends BaseAttributeTestCase
+final class TemplateUseAttributeTest extends BaseAttributeTestCase
 {
     public function testTraitTemplateUseAttribute(): void
     {
diff --git a/tests/TypeAttributeTest.php b/tests/TypeAttributeTest.php
index eec5ff4..bb0416f 100644
--- a/tests/TypeAttributeTest.php
+++ b/tests/TypeAttributeTest.php
@@ -4,7 +4,7 @@
 
 namespace test\PhpStaticAnalysis\PsalmPlugin;
 
-class TypeAttributeTest extends BaseAttributeTestCase
+final class TypeAttributeTest extends BaseAttributeTestCase
 {
     public function testPropertyTypeAttribute(): void
     {