diff --git a/lib/AdapterRpc.php b/lib/AdapterRpc.php
index 5b56259e..4d5bd9b3 100644
--- a/lib/AdapterRpc.php
+++ b/lib/AdapterRpc.php
@@ -707,7 +707,7 @@ public function getResourceCapabilities(string $spEntityId, array $userGroups, s
                 continue;
             }
             $resourceCapabilities = $this->connector->get('attributesManager', 'getAttribute', [
-                'resource' => $resource['id'],
+                'resource' => $resource->getId(),
                 'attributeName' => 'urn:perun:resource:attribute-def:def:capabilities',
             ]);
 
@@ -720,7 +720,7 @@ public function getResourceCapabilities(string $spEntityId, array $userGroups, s
             $resourceCapabilities = $resourceCapabilities['value'];
 
             $resourceGroups = $this->connector->get('resourcesManager', 'getAssignedGroups', [
-                'resource' => $resource['id'],
+                'resource' => $resource->getId(),
             ]);
 
             if (empty($resourceGroups)) {