diff --git a/Contrib/less.php/Less.php b/Contrib/less.php/Less.php
index b595c00ed..32ad49225 100644
--- a/Contrib/less.php/Less.php
+++ b/Contrib/less.php/Less.php
@@ -9332,7 +9332,7 @@ public function visitRuleset( $rulesetNode, &$visitDeeper ){
 
 
 		// Compile rules and rulesets
-		$nodeRuleCnt = count($rulesetNode->rules);
+		$nodeRuleCnt = (is_array($rulesetNode->rules) || $rulesetNode->rules instanceof Countable) ? count($rulesetNode->rules) : 0;
 		for( $i = 0; $i < $nodeRuleCnt; ){
 			$rule = $rulesetNode->rules[$i];