diff --git a/src/Protocol/ActivityPub/ClientToServer.php b/src/Protocol/ActivityPub/ClientToServer.php
index 65d4a77d21..4f3a8268b0 100644
--- a/src/Protocol/ActivityPub/ClientToServer.php
+++ b/src/Protocol/ActivityPub/ClientToServer.php
@@ -323,7 +323,7 @@ class ClientToServer
 			$requester_id = Contact::getIdForURL($requester, $owner['uid']);
 			if (!empty($requester_id)) {
 				$permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
-				if (count($permissionSets)) {
+				if (count($permissionSets) > 0) {
 					$condition = ['psid' => array_merge($permissionSets->column('id'),
 						[DI::permissionSet()->selectPublicForUser($owner['uid'])])];
 				}
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index 41847a79a8..3e8ad6ff8d 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -619,7 +619,7 @@ class Receiver
 		}
 
 		$actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
-		if (empty($actor)) {
+		if ($actor === null || $actor === '') {
 			Logger::info('Empty actor', ['activity' => $activity]);
 			return true;
 		}
@@ -642,7 +642,7 @@ class Receiver
 
 		// Test the provided signatures against the actor and "attributedTo"
 		if ($trust_source) {
-			if (!empty($attributed_to) && $actor !== null) {
+			if ($attributed_to !== false && $attributed_to !== '') {
 				$trust_source = (in_array($actor, $signer) && in_array($attributed_to, $signer));
 			} else {
 				$trust_source = in_array($actor, $signer);