1 files changed, 8 insertions, 3 deletions
diff --git a/lib/Thread/Task.pm b/lib/Thread/Task.pm
index 86a1387..5567805 100644
--- a/lib/Thread/Task.pm
+++ b/lib/Thread/Task.pm
@@ -102,9 +102,14 @@ class Thread::Task {
             die "Can't update between different task classes";
         }
         for my $attr ($self->meta->get_all_attributes) {
-            $attr->set_value($self,
-                             $attr->get_value($new_task)
-                         );
+            if ($attr->has_value($new_task)) {
+                $attr->set_value($self,
+                                 $attr->get_value($new_task)
+                             );
+            }
+            else {
+                $attr->clear_value($self);
+            }
         }
         return;
     }