diff --git a/src/Concerns/ManagesUsageBilling.php b/src/Concerns/ManagesUsageBilling.php
index c6d75d0f..374e34ad 100644
--- a/src/Concerns/ManagesUsageBilling.php
+++ b/src/Concerns/ManagesUsageBilling.php
@@ -59,7 +59,7 @@ public function meterEventSummaries(string $meterId, int $startTime = 1, ?int $e
     {
         $this->assertCustomerExists();
 
-        if (!isset($endTime)) {
+        if (! isset($endTime)) {
             $endTime = time();
         }