diff --git a/src/Type/Definition/Directive.php b/src/Type/Definition/Directive.php
index 0a6db42e5..f2c546f93 100644
--- a/src/Type/Definition/Directive.php
+++ b/src/Type/Definition/Directive.php
@@ -33,7 +33,7 @@ class Directive
      *
      * @var array<string, Directive>
      */
-    protected static array $internalDirectives;
+    protected static array $internalDirectives = [];
 
     public string $name;
 
@@ -90,7 +90,11 @@ public static function includeDirective(): Directive
      */
     public static function getInternalDirectives(): array
     {
-        return self::$internalDirectives ??= [
+        if (self::$internalDirectives !== []) {
+            return self::$internalDirectives;
+        }
+
+        return self::$internalDirectives = [
             'include' => new self([
                 'name' => self::INCLUDE_NAME,
                 'description' => 'Directs the executor to include this field or fragment only when the `if` argument is true.',
@@ -162,4 +166,9 @@ public static function isSpecifiedDirective(Directive $directive): bool
     {
         return \array_key_exists($directive->name, self::getInternalDirectives());
     }
+
+    public static function reset(): void
+    {
+        self::$internalDirectives = [];
+    }
 }
diff --git a/src/Type/Definition/Type.php b/src/Type/Definition/Type.php
index cd734b99c..e757e7d32 100644
--- a/src/Type/Definition/Type.php
+++ b/src/Type/Definition/Type.php
@@ -31,7 +31,7 @@ abstract class Type implements \JsonSerializable
     ];
 
     /** @var array<string, ScalarType> */
-    protected static array $standardTypes;
+    protected static array $standardTypes = [];
 
     /**
      * @api
@@ -261,4 +261,9 @@ public function jsonSerialize(): string
     {
         return $this->toString();
     }
+
+    public static function reset(): void
+    {
+        static::$standardTypes = [];
+    }
 }
diff --git a/tests/Type/Definition/TypeTest.php b/tests/Type/Definition/TypeTest.php
new file mode 100644
index 000000000..b123a26aa
--- /dev/null
+++ b/tests/Type/Definition/TypeTest.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+namespace GraphQL\Tests\Type\Definition;
+
+use GraphQL\Type\Definition\Type;
+use PHPUnit\Framework\TestCase;
+
+final class TypeTest extends TestCase
+{
+    public function testReset(): void
+    {
+        $stringType = Type::string();
+
+        Type::reset();
+
+        self::assertNotSame($stringType, Type::string());
+    }
+}
diff --git a/tests/Type/DirectiveTest.php b/tests/Type/DirectiveTest.php
index fae3c7c61..b9ff9757e 100644
--- a/tests/Type/DirectiveTest.php
+++ b/tests/Type/DirectiveTest.php
@@ -83,5 +83,14 @@ public function testDefinesADirectiveWithMultipleArgs(): void
         self::assertFalse($argumentBar->isDeprecated());
     }
 
+    public function testReset(): void
+    {
+        $directives = Directive::getInternalDirectives();
+
+        Directive::reset();
+
+        self::assertNotSame($directives, Directive::getInternalDirectives());
+    }
+
     // TODO implement all of https://github.com/graphql/graphql-js/blob/master/src/type/__tests__/directive-test.js
 }