diff --git a/GrpcTrait.php b/GrpcTrait.php
index 355feee..7fe3c45 100644
--- a/GrpcTrait.php
+++ b/GrpcTrait.php
@@ -251,7 +251,7 @@ private function formatTimestampForApi($value)
     {
         preg_match('/\.(\d{1,9})Z/', $value, $matches);
         $value = preg_replace('/\.(\d{1,9})Z/', '.000000Z', $value);
-        $dt = \DateTimeImmutable::createFromFormat('Y-m-d\TH:i:s.u\Z', $value);
+        $dt = \DateTimeImmutable::createFromFormat('Y-m-d\TH:i:s.u\Z', $value, new \DateTimeZone('UTC'));
         $nanos = (isset($matches[1])) ? str_pad($matches[1], 9, '0') : 0;
 
         return [