diff --git a/blockbot/blockbot.php b/blockbot/blockbot.php
index 022f188d..8f56a553 100644
--- a/blockbot/blockbot.php
+++ b/blockbot/blockbot.php
@@ -209,7 +209,7 @@ function blockbot_log_activitypub(string $url, string $agent)
 		blockbot_save('activitypub-inbox-agents', $agent);
 	}
 
-	if (!empty($_SERVER['HTTP_SIGNATURE']) && !empty(HTTPSignature::getSigner('', $_SERVER))) {
+	if (!empty($_SERVER['HTTP_SIGNATURE']) && !empty(HTTPSignature::getSigner('', $_SERVER, false))) {
 		blockbot_save('activitypub-signature-agents', $agent);
 	}
 }