diff --git a/module/task/model.php b/module/task/model.php
index 8f4e4830c5..127475f241 100755
--- a/module/task/model.php
+++ b/module/task/model.php
@@ -172,7 +172,7 @@ class taskModel extends model
 
             if(strpos($requiredFields, ',estStarted,') !== false and !isset($task->estStarted)) dao::$errors['estStarted'] = sprintf($this->lang->error->notempty, $this->lang->task->estStarted);
             if(strpos($requiredFields, ',deadline,') !== false and !isset($task->deadline)) dao::$errors['deadline'] = sprintf($this->lang->error->notempty, $this->lang->task->deadline);
-            if(isset($task->estStarted) and isset($task->deadline) and !helper::isZeroDate($task->deadline) and $task->deadline <= $task->estStarted) dao::$errors['deadline'] = sprintf($this->lang->error->ge, $this->lang->task->deadline, $task->estStarted);
+            if(isset($task->estStarted) and isset($task->deadline) and !helper::isZeroDate($task->deadline) and $task->deadline < $task->estStarted) dao::$errors['deadline'] = sprintf($this->lang->error->ge, $this->lang->task->deadline, $task->estStarted);
 
             if(dao::isError()) return false;