diff --git a/tests/e2e/Services/Sites/SitesCustomServerTest.php b/tests/e2e/Services/Sites/SitesCustomServerTest.php
index d28e2fe8b4..c8301b9428 100644
--- a/tests/e2e/Services/Sites/SitesCustomServerTest.php
+++ b/tests/e2e/Services/Sites/SitesCustomServerTest.php
@@ -2775,11 +2775,13 @@ class SitesCustomServerTest extends Scope
         $proxyClient->setEndpoint('http://' . $domain);
 
         $response = $proxyClient->call(Client::METHOD_GET, '/cookies', [
-            'cookie' => 'custom-session-id=abcd123'
+            'cookie' => 'custom-session-id=abcd123; custom-user-id=efgh456'
         ]);
 
         $this->assertEquals(200, $response['headers']['status-code']);
-        $this->assertEquals("abcd123", $response['body']);
+        $this->assertEquals("abcd123;efgh456", $response['body']);
+        $this->assertEquals("value-one", $response['cookies']['my-cookie-one']);
+        $this->assertEquals("value-two", $response['cookies']['my-cookie-two']);
 
         $this->cleanupSite($siteId);
     }
diff --git a/tests/resources/sites/astro/src/pages/cookies.js b/tests/resources/sites/astro/src/pages/cookies.js
index 5f5efac833..65911c8aeb 100644
--- a/tests/resources/sites/astro/src/pages/cookies.js
+++ b/tests/resources/sites/astro/src/pages/cookies.js
@@ -1,4 +1,9 @@
 export async function GET(context) {
   const sessionId = context.cookies.get("custom-session-id")?.value ?? 'Custom session ID missing';
-  return new Response(sessionId);
+  const userId = context.cookies.get("custom-user-id")?.value ?? 'Custom user ID missing';
+
+  context.cookies.set('my-cookie-one', 'value-one');
+  context.cookies.set('my-cookie-two', 'value-two');
+
+  return new Response(sessionId + ";" + userId);
 }