diff --git a/src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldInt.php b/src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldInt.php
--- a/src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldInt.php
+++ b/src/infrastructure/customfield/standard/PhabricatorStandardCustomFieldInt.php
@@ -24,7 +24,7 @@
 
   public function getValueForStorage() {
     $value = $this->getFieldValue();
-    if (strlen($value)) {
+    if (phutil_nonempty_string($value)) {
       return $value;
     } else {
       return null;