diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index bda45f1b..92a1a9c8 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -15,6 +15,7 @@ jobs:
           - "8.1"
           - "8.2"
           - "8.3"
+          - "8.4"
 
     env:
       php-extensions: ds,yaml
@@ -33,6 +34,7 @@ jobs:
       - uses: "ramsey/composer-install@v2"
         with:
           dependency-versions: ${{ matrix.dependencies }}
+          composer-options: "--ignore-platform-reqs" # Remove when Psalm supports PHP 8.4 / @see https://github.com/vimeo/psalm/pull/10928
 
       - name: Running unit tests
         run: php vendor/bin/phpunit --testsuite=unit
diff --git a/composer.json b/composer.json
index e9a9226b..3113cb2f 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
         }
     ],
     "require": {
-        "php": "~8.1.0 || ~8.2.0 || ~8.3.0",
+        "php": "~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0",
         "composer-runtime-api": "^2.0",
         "psr/simple-cache": "^1.0 || ^2.0 || ^3.0"
     },
diff --git a/composer.lock b/composer.lock
index 5fee4489..474705b0 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "d8ad2085ad373dd8ded5f55b062aab34",
+    "content-hash": "410dad193a0cb42759cf51b835de7831",
     "packages": [
         {
             "name": "psr/simple-cache",
@@ -1185,12 +1185,12 @@
             "version": "v5.2.13",
             "source": {
                 "type": "git",
-                "url": "https://github.com/justinrainbow/json-schema.git",
+                "url": "https://github.com/jsonrainbow/json-schema.git",
                 "reference": "fbbe7e5d79f618997bc3332a6f49246036c45793"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/justinrainbow/json-schema/zipball/fbbe7e5d79f618997bc3332a6f49246036c45793",
+                "url": "https://api.github.com/repos/jsonrainbow/json-schema/zipball/fbbe7e5d79f618997bc3332a6f49246036c45793",
                 "reference": "fbbe7e5d79f618997bc3332a6f49246036c45793",
                 "shasum": ""
             },
@@ -5484,13 +5484,13 @@
     ],
     "aliases": [],
     "minimum-stability": "stable",
-    "stability-flags": [],
+    "stability-flags": {},
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": "~8.1.0 || ~8.2.0 || ~8.3.0",
+        "php": "~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0",
         "composer-runtime-api": "^2.0"
     },
-    "platform-dev": [],
+    "platform-dev": {},
     "plugin-api-version": "2.6.0"
 }
diff --git a/src/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepository.php b/src/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepository.php
index 59c61519..7daab277 100644
--- a/src/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepository.php
+++ b/src/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepository.php
@@ -19,6 +19,7 @@
 
 use function array_map;
 use function str_ends_with;
+use function str_starts_with;
 
 /** @internal */
 final class ReflectionFunctionDefinitionRepository implements FunctionDefinitionRepository
@@ -57,7 +58,8 @@ public function for(callable $function): FunctionDefinition
         $class = $reflection->getClosureScopeClass();
         $returnType = $returnTypeResolver->resolveReturnTypeFor($reflection);
         $nativeReturnType = $returnTypeResolver->resolveNativeReturnTypeFor($reflection);
-        $isClosure = $name === '{closure}' || str_ends_with($name, '\\{closure}');
+        // PHP8.2 use `ReflectionFunction::isAnonymous()`
+        $isClosure = $name === '{closure}' || str_ends_with($name, '\\{closure}') || str_starts_with($name, '{closure:');
 
         if ($returnType instanceof UnresolvableType) {
             $returnType = $returnType->forFunctionReturnType($signature);
@@ -83,7 +85,8 @@ public function for(callable $function): FunctionDefinition
      */
     private function signature(ReflectionFunction $reflection): string
     {
-        if (str_contains($reflection->name, '{closure}')) {
+        // PHP8.2 use `ReflectionFunction::isAnonymous()`
+        if ($reflection->name === '{closure}' || str_ends_with($reflection->name, '\\{closure}') || str_starts_with($reflection->name, '{closure:')) {
             $startLine = $reflection->getStartLine();
             $endLine = $reflection->getEndLine();
 
diff --git a/tests/Functional/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepositoryTest.php b/tests/Functional/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepositoryTest.php
index 95b6a465..306942ec 100644
--- a/tests/Functional/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepositoryTest.php
+++ b/tests/Functional/Definition/Repository/Reflection/ReflectionFunctionDefinitionRepositoryTest.php
@@ -39,7 +39,11 @@ public function test_function_data_can_be_retrieved(): void
         $function = $this->repository->for($callback);
         $parameters = $function->parameters;
 
-        self::assertSame(__NAMESPACE__ . '\{closure}', $function->name);
+        if (PHP_VERSION_ID < 8_04_00) {
+            self::assertSame(__NAMESPACE__ . '\{closure}', $function->name);
+        } else {
+            self::assertSame('{closure:' . self::class . '::' . __FUNCTION__ . '():37}', $function->name);
+        }
         self::assertInstanceOf(NativeStringType::class, $function->returnType);
 
         self::assertTrue($parameters->has('foo'));
diff --git a/tests/Functional/Definition/Repository/Reflection/TypeResolver/ReflectionTypeResolverTest.php b/tests/Functional/Definition/Repository/Reflection/TypeResolver/ReflectionTypeResolverTest.php
index 76fad582..19687a64 100644
--- a/tests/Functional/Definition/Repository/Reflection/TypeResolver/ReflectionTypeResolverTest.php
+++ b/tests/Functional/Definition/Repository/Reflection/TypeResolver/ReflectionTypeResolverTest.php
@@ -98,7 +98,7 @@ public static function native_type_is_resolved_properly_data_provider(): iterabl
     }
 
     // PHP8.2 move to data provider
-    #[RequiresPhp('8.2')]
+    #[RequiresPhp('>=8.2')]
     public function test_disjunctive_normal_form_type_is_resolved_properly(): void
     {
         $reflectionType = (new ReflectionProperty(ObjectWithPropertyWithNativeDisjunctiveNormalFormType::class, 'someProperty'))->getType();
@@ -109,7 +109,7 @@ public function test_disjunctive_normal_form_type_is_resolved_properly(): void
     }
 
     // PHP8.2 move to data provider
-    #[RequiresPhp('8.2')]
+    #[RequiresPhp('>=8.2')]
     public function test_native_null_type_is_resolved_properly(): void
     {
         $reflectionType = (new ReflectionProperty(ObjectWithPropertyWithNativePhp82StandaloneTypes::class, 'nativeNull'))->getType();
@@ -120,7 +120,7 @@ public function test_native_null_type_is_resolved_properly(): void
     }
 
     // PHP8.2 move to data provider
-    #[RequiresPhp('8.2')]
+    #[RequiresPhp('>=8.2')]
     public function test_native_true_type_is_resolved_properly(): void
     {
         $reflectionType = (new ReflectionProperty(ObjectWithPropertyWithNativePhp82StandaloneTypes::class, 'nativeTrue'))->getType();
@@ -131,7 +131,7 @@ public function test_native_true_type_is_resolved_properly(): void
     }
 
     // PHP8.2 move to data provider
-    #[RequiresPhp('8.2')]
+    #[RequiresPhp('>=8.2')]
     public function test_native_false_type_is_resolved_properly(): void
     {
         $reflectionType = (new ReflectionProperty(ObjectWithPropertyWithNativePhp82StandaloneTypes::class, 'nativeFalse'))->getType();