diff --git a/vendor/magento/module-staging/Model/Update/UpdateValidator.php b/vendor/magento/module-staging/Model/Update/UpdateValidator.php
index 3be0dab0ba0..66add0f097e 100644
--- a/vendor/magento/module-staging/Model/Update/UpdateValidator.php
+++ b/vendor/magento/module-staging/Model/Update/UpdateValidator.php
@@ -43,14 +43,12 @@ class UpdateValidator
     {
         /** @var \DateTime $currentDateTime */
         $currentDateTime = new \DateTime();
+        $startTime = strtotime($stagingData['start_time']);
+        $updateStartTime = $update->getStartTime() ? strtotime($update->getStartTime()) : 0;
 
-        if ((strtotime($stagingData['start_time']) < $currentDateTime->getTimestamp())
-            && (strtotime($update->getStartTime()) !== strtotime($stagingData['start_time']))
-        ) {
+        if ($updateStartTime < $currentDateTime->getTimestamp() && $updateStartTime !== $startTime) {
             throw new LocalizedException(
-                __(
-                    "The Start Time of this Update cannot be changed. It's been already started."
-                )
+                __("The Start Time of this Update cannot be changed. It's been already started.")
             );
         }
     }