diff --git a/taskman.inc.php b/taskman.inc.php
index 2a27f60..cc9473f 100644
--- a/taskman.inc.php
+++ b/taskman.inc.php
@@ -293,11 +293,7 @@ function _get_task_candidates()
 
   //get tasks defined as closures
   foreach($TASKMAN_CLOSURES as $name => $args)
-  {
-    if(isset($cands[$name]))
-      throw new Exception("Task '$name' is already defined");
     $cands[$name] = $args;
-  }
 
   ksort($cands);
 
@@ -385,6 +381,10 @@ function task($name)
 {
   global $TASKMAN_CLOSURES;
 
+  //TODO: can it be a feature?
+  if(isset($TASKMAN_CLOSURES[$name]))
+    throw new TaskmanException("Task '$name' is already defined");
+
   $args = func_get_args();
   $TASKMAN_CLOSURES[$name] = $args; 
 }