diff --git a/module/task/ui/common.field.php b/module/task/ui/common.field.php
index 919849a151..69d58b2220 100644
--- a/module/task/ui/common.field.php
+++ b/module/task/ui/common.field.php
@@ -21,7 +21,7 @@ $fields->field('name')
 
 $fields->field('datePlan')
     ->lable($lang->task->datePlan)
-    ->required(strpos($config->task->create->requiredFields, 'estStarted') || strpos($config->task->create->requiredFields, 'deadline'))
+    ->required(strpos($config->task->create->requiredFields, 'estStarted') !== false || strpos($config->task->create->requiredFields, 'deadline') !== false)
     ->control('inputGroup')
     ->itemBegin('estStarted')->control('datePicker')->placeholder($lang->task->estStarted)->value(data('task.estStarted'))->itemEnd()
     ->item(array('control' => 'span', 'text' => '-'))