diff --git a/src/Framework/Attributes/RunClassInSeparateProcess.php b/src/Framework/Attributes/RunClassInSeparateProcess.php
index 1ccd3bc6fb..e8918e5494 100644
--- a/src/Framework/Attributes/RunClassInSeparateProcess.php
+++ b/src/Framework/Attributes/RunClassInSeparateProcess.php
@@ -19,4 +19,15 @@
 #[Attribute(Attribute::TARGET_CLASS)]
 final readonly class RunClassInSeparateProcess
 {
+    private ?bool $forkIfPossible;
+
+    public function __construct(bool $forkIfPossible = null)
+    {
+        $this->forkIfPossible = $forkIfPossible;
+    }
+
+    public function forkIfPossible(): ?bool
+    {
+        return $this->forkIfPossible;
+    }
 }
diff --git a/src/Framework/Attributes/RunInSeparateProcess.php b/src/Framework/Attributes/RunInSeparateProcess.php
index 838e267e2e..d10cbba3ef 100644
--- a/src/Framework/Attributes/RunInSeparateProcess.php
+++ b/src/Framework/Attributes/RunInSeparateProcess.php
@@ -19,4 +19,15 @@
 #[Attribute(Attribute::TARGET_METHOD)]
 final readonly class RunInSeparateProcess
 {
+    private ?bool $forkIfPossible;
+
+    public function __construct(?bool $forkIfPossible = null)
+    {
+        $this->forkIfPossible = $forkIfPossible;
+    }
+
+    public function forkIfPossible(): ?bool
+    {
+        return $this->forkIfPossible;
+    }
 }
diff --git a/src/Framework/Attributes/RunTestsInSeparateProcesses.php b/src/Framework/Attributes/RunTestsInSeparateProcesses.php
index 19fea88239..ed804fa2a7 100644
--- a/src/Framework/Attributes/RunTestsInSeparateProcesses.php
+++ b/src/Framework/Attributes/RunTestsInSeparateProcesses.php
@@ -19,4 +19,15 @@
 #[Attribute(Attribute::TARGET_CLASS)]
 final readonly class RunTestsInSeparateProcesses
 {
+    private ?bool $forkIfPossible;
+
+    public function __construct(?bool $forkIfPossible = null)
+    {
+        $this->forkIfPossible = $forkIfPossible;
+    }
+
+    public function forkIfPossible(): ?bool
+    {
+        return $this->forkIfPossible;
+    }
 }
diff --git a/src/Metadata/Metadata.php b/src/Metadata/Metadata.php
index d9a787b731..ce1296974c 100644
--- a/src/Metadata/Metadata.php
+++ b/src/Metadata/Metadata.php
@@ -390,19 +390,19 @@ public static function requiresSettingOnMethod(string $setting, string $value):
         return new RequiresSetting(self::METHOD_LEVEL, $setting, $value);
     }
 
-    public static function runClassInSeparateProcess(): RunClassInSeparateProcess
+    public static function runClassInSeparateProcess(?bool $forkIfPossible = null): RunClassInSeparateProcess
     {
-        return new RunClassInSeparateProcess(self::CLASS_LEVEL);
+        return new RunClassInSeparateProcess(self::CLASS_LEVEL, $forkIfPossible);
     }
 
-    public static function runTestsInSeparateProcesses(): RunTestsInSeparateProcesses
+    public static function runTestsInSeparateProcesses(?bool $forkIfPossible = null): RunTestsInSeparateProcesses
     {
-        return new RunTestsInSeparateProcesses(self::CLASS_LEVEL);
+        return new RunTestsInSeparateProcesses(self::CLASS_LEVEL, $forkIfPossible);
     }
 
-    public static function runInSeparateProcess(): RunInSeparateProcess
+    public static function runInSeparateProcess(?bool $forkIfPossible = null): RunInSeparateProcess
     {
-        return new RunInSeparateProcess(self::METHOD_LEVEL);
+        return new RunInSeparateProcess(self::METHOD_LEVEL, $forkIfPossible);
     }
 
     public static function test(): Test
diff --git a/src/Metadata/Parser/AttributeParser.php b/src/Metadata/Parser/AttributeParser.php
index 257c38e328..8b19fa387c 100644
--- a/src/Metadata/Parser/AttributeParser.php
+++ b/src/Metadata/Parser/AttributeParser.php
@@ -297,12 +297,20 @@ public function forClass(string $className): MetadataCollection
                     break;
 
                 case RunClassInSeparateProcess::class:
-                    $result[] = Metadata::runClassInSeparateProcess();
+                    assert($attributeInstance instanceof RunClassInSeparateProcess);
+
+                    $result[] = Metadata::runClassInSeparateProcess(
+                        $attributeInstance->forkIfPossible(),
+                    );
 
                     break;
 
                 case RunTestsInSeparateProcesses::class:
-                    $result[] = Metadata::runTestsInSeparateProcesses();
+                    assert($attributeInstance instanceof RunTestsInSeparateProcesses);
+
+                    $result[] = Metadata::runTestsInSeparateProcesses(
+                        $attributeInstance->forkIfPossible(),
+                    );
 
                     break;
 
@@ -638,7 +646,11 @@ public function forMethod(string $className, string $methodName): MetadataCollec
                     break;
 
                 case RunInSeparateProcess::class:
-                    $result[] = Metadata::runInSeparateProcess();
+                    assert($attributeInstance instanceof RunInSeparateProcess);
+
+                    $result[] = Metadata::runInSeparateProcess(
+                        $attributeInstance->forkIfPossible(),
+                    );
 
                     break;
 
diff --git a/src/Metadata/RunClassInSeparateProcess.php b/src/Metadata/RunClassInSeparateProcess.php
index 907a45d452..a5b6aa7f82 100644
--- a/src/Metadata/RunClassInSeparateProcess.php
+++ b/src/Metadata/RunClassInSeparateProcess.php
@@ -16,6 +16,23 @@
  */
 final readonly class RunClassInSeparateProcess extends Metadata
 {
+    private ?bool $forkIfPossible;
+
+    /**
+     * @psalm-param 0|1 $level
+     */
+    protected function __construct(int $level, ?bool $forkIfPossible = null)
+    {
+        $this->forkIfPossible = $forkIfPossible;
+
+        parent::__construct($level);
+    }
+
+    public function forkIfPossible(): ?bool
+    {
+        return $this->forkIfPossible;
+    }
+
     /**
      * @psalm-assert-if-true RunClassInSeparateProcess $this
      */
diff --git a/src/Metadata/RunInSeparateProcess.php b/src/Metadata/RunInSeparateProcess.php
index 07febae09d..9b5cc237b0 100644
--- a/src/Metadata/RunInSeparateProcess.php
+++ b/src/Metadata/RunInSeparateProcess.php
@@ -16,6 +16,23 @@
  */
 final readonly class RunInSeparateProcess extends Metadata
 {
+    private ?bool $forkIfPossible;
+
+    /**
+     * @psalm-param 0|1 $level
+     */
+    protected function __construct(int $level, ?bool $forkIfPossible = null)
+    {
+        $this->forkIfPossible = $forkIfPossible;
+
+        parent::__construct($level);
+    }
+
+    public function forkIfPossible(): ?bool
+    {
+        return $this->forkIfPossible;
+    }
+
     /**
      * @psalm-assert-if-true RunInSeparateProcess $this
      */
diff --git a/src/Metadata/RunTestsInSeparateProcesses.php b/src/Metadata/RunTestsInSeparateProcesses.php
index b71233d3db..5a8275d293 100644
--- a/src/Metadata/RunTestsInSeparateProcesses.php
+++ b/src/Metadata/RunTestsInSeparateProcesses.php
@@ -16,6 +16,23 @@
  */
 final readonly class RunTestsInSeparateProcesses extends Metadata
 {
+    private ?bool $forkIfPossible;
+
+    /**
+     * @psalm-param 0|1 $level
+     */
+    protected function __construct(int $level, ?bool $forkIfPossible = null)
+    {
+        $this->forkIfPossible = $forkIfPossible;
+
+        parent::__construct($level);
+    }
+
+    public function forkIfPossible(): ?bool
+    {
+        return $this->forkIfPossible;
+    }
+
     /**
      * @psalm-assert-if-true RunTestsInSeparateProcesses $this
      */