diff --git a/src/Consumer/ConsumerFactory.php b/src/Consumer/ConsumerFactory.php
index b63f5bf..a412e9a 100644
--- a/src/Consumer/ConsumerFactory.php
+++ b/src/Consumer/ConsumerFactory.php
@@ -57,11 +57,11 @@ private function create(string $name): Consumer
 		$prefetchSize = null;
 		$prefetchCount = null;
 
-		if (($consumerData['qos']['prefetchSize'] ?? null) !== null) {
+		if (isset($consumerData['qos']['prefetchSize'])) {
 			$prefetchSize = $consumerData['qos']['prefetchSize'];
 		}
 
-		if (($consumerData['qos']['prefetchCount'] ?? null) !== null) {
+		if (isset($consumerData['qos']['prefetchCount'])) {
 			$prefetchCount = $consumerData['qos']['prefetchCount'];
 		}