diff --git a/lib/models/resources/ResourceRequest.class.php b/lib/models/resources/ResourceRequest.class.php
index 0f1a3a6c6b6b980b2e3242425e4112fc5a90ed83..7f9e3c6eb2ccb34335ff6b587af5745cb4a77d54 100644
--- a/lib/models/resources/ResourceRequest.class.php
+++ b/lib/models/resources/ResourceRequest.class.php
@@ -2430,10 +2430,12 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
 
     public function getPriority()
     {
-        if (!isset($this->getTimeIntervals()[0])) {
-            return 0;
+
+        $result = $this->getTimeIntervals();
+        if (count($result) === 0) {
+            return null;
         }
-        $first = $this->getTimeIntervals()[0];
+        $first = $result[0];
         return round(($first['begin'] - time()) / 86400);
     }