diff --git a/src/Rules/Challenge.php b/src/Rules/Challenge.php
index 1d11da8..f08ff6e 100644
--- a/src/Rules/Challenge.php
+++ b/src/Rules/Challenge.php
@@ -8,6 +8,7 @@ class Challenge extends Rule
 {
     public const TYPE_CAPTCHA = 'captcha';
     public const TYPE_CUSTOM = 'custom';
+    public const TYPE_COMPUTE = 'compute';
 
     private string $type;
 
@@ -17,7 +18,7 @@ class Challenge extends Rule
     public function __construct(array $conditions = [], string $type = self::TYPE_CAPTCHA)
     {
         parent::__construct($conditions);
-        if (!in_array($type, [self::TYPE_CAPTCHA, self::TYPE_CUSTOM], true)) {
+        if (!in_array($type, [self::TYPE_CAPTCHA, self::TYPE_CUSTOM, self::TYPE_COMPUTE], true)) {
             throw new \InvalidArgumentException('Invalid challenge type: ' . $type);
         }
         $this->type = $type;
diff --git a/tests/RulesTest.php b/tests/RulesTest.php
index 4b848d5..25655ee 100644
--- a/tests/RulesTest.php
+++ b/tests/RulesTest.php
@@ -36,10 +36,18 @@ public function testChallengeRuleTypeDefaults(): void
     {
         $defaultRule = new Challenge();
         $customRule = new Challenge([], Challenge::TYPE_CUSTOM);
+        $computeRule = new Challenge([], Challenge::TYPE_COMPUTE);
 
         $this->assertSame('challenge', $defaultRule->getAction());
         $this->assertSame(Challenge::TYPE_CAPTCHA, $defaultRule->getType());
         $this->assertSame(Challenge::TYPE_CUSTOM, $customRule->getType());
+        $this->assertSame(Challenge::TYPE_COMPUTE, $computeRule->getType());
+    }
+
+    public function testChallengeRuleRejectsUnknownType(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+        new Challenge([], 'not-a-real-type');
     }
 
     public function testRateLimitMetadata(): void