diff --git a/src/Readability.php b/src/Readability.php
index 6bcbf78d..e7736492 100644
--- a/src/Readability.php
+++ b/src/Readability.php
@@ -1076,7 +1076,7 @@ private function rateNodes($nodes)
             $scoreThreshold = $lastScore / 3;
 
             /* @var DOMElement $parentOfTopCandidate */
-            while ($parentOfTopCandidate->nodeName !== 'body') {
+            while (!is_null($parentOfTopCandidate) && $parentOfTopCandidate->nodeName !== 'body') {
                 $parentScore = $parentOfTopCandidate->contentScore;
                 if ($parentScore < $scoreThreshold) {
                     break;