diff --git a/src/Handler/CloudWatch.php b/src/Handler/CloudWatch.php
index 064a7b8..b7d8703 100755
--- a/src/Handler/CloudWatch.php
+++ b/src/Handler/CloudWatch.php
@@ -210,7 +210,7 @@ private function formatRecord(array $entry)
     {
         return [
             'message' => $entry['formatted'],
-            'timestamp' => floatval(substr_replace($entry['datetime']->format('Uu'), '.', -4, 0))
+            'timestamp' => $entry['datetime']->format('U.u') * 1000
         ];
     }