diff --git a/site/app/Http/FetchMetadata/ResourceIsolationPolicy.php b/site/app/Http/FetchMetadata/ResourceIsolationPolicy.php
index 605aa1ea7..ea3ec145b 100644
--- a/site/app/Http/FetchMetadata/ResourceIsolationPolicy.php
+++ b/site/app/Http/FetchMetadata/ResourceIsolationPolicy.php
@@ -32,7 +32,17 @@ public function install(): void
 				$presenter->onStartup[] = function () use ($presenter): void {
 					if (!$this->isRequestAllowed($presenter)) {
 						if ($this->reportOnly) {
-							$message = sprintf('%s %s %s', $this->httpRequest->getMethod(), $presenter->getAction(true), implode(', ', array_keys($presenter->getParameters())));
+							$headers = [];
+							foreach ($this->fetchMetadata->getAllHeaders() as $header => $value) {
+								$headers[] = sprintf('%s: %s', $header, $value ?? '[not sent]');
+							}
+							$message = sprintf(
+								'%s %s; param names: %s; headers: %s',
+								$this->httpRequest->getMethod(),
+								$presenter->getAction(true),
+								implode(', ', array_keys($presenter->getParameters())),
+								implode(', ', $headers),
+							);
 							Debugger::log($message, 'cross-site');
 						} else {
 							$presenter->forward(':Www:Forbidden:', ['message' => 'messages.forbidden.crossSite']);
diff --git a/site/tests/Http/FetchMetadata/ResourceIsolationPolicyTest.phpt b/site/tests/Http/FetchMetadata/ResourceIsolationPolicyTest.phpt
index 5e0a7a0db..a821efb43 100644
--- a/site/tests/Http/FetchMetadata/ResourceIsolationPolicyTest.phpt
+++ b/site/tests/Http/FetchMetadata/ResourceIsolationPolicyTest.phpt
@@ -68,7 +68,7 @@ class ResourceIsolationPolicyTest extends TestCase
 		$this->installPolicy(true);
 		$this->httpRequest->setHeader(FetchMetadataHeader::Site->value, 'cross-site');
 		$this->callPresenterAction();
-		Assert::same(['GET :Www:Homepage:default foo, waldo'], $this->logger->getLogged());
+		Assert::same(['GET :Www:Homepage:default; param names: foo, waldo; headers: Sec-Fetch-Dest: [not sent], Sec-Fetch-Mode: [not sent], Sec-Fetch-Site: cross-site, Sec-Fetch-User: [not sent]'], $this->logger->getLogged());
 		Assert::same(IResponse::S200_OK, $this->httpResponse->getCode());
 	}