diff --git a/atdb/taskdatabase/templates/taskdatabase/index.html b/atdb/taskdatabase/templates/taskdatabase/index.html
index 58804fffcf1fb54bab14f6c5471c47d49e8f88c1..cf17fba983f530a092ccf04a26c7d88f90bbbd26 100644
--- a/atdb/taskdatabase/templates/taskdatabase/index.html
+++ b/atdb/taskdatabase/templates/taskdatabase/index.html
@@ -80,7 +80,7 @@
         {% include 'taskdatabase/pagination.html' %}
        </div>
     </div>
-    <p class="footer"> Version 1.0.0 (28 oct 2021 - 11:30)
+    <p class="footer"> Version 1.0.0 (28 oct 2021 - 14:00)
 
 </div>
 
diff --git a/atdb/taskdatabase/views.py b/atdb/taskdatabase/views.py
index 977f0088e5b643a76d0cf4653f1f92a3f291bcfe..4fd71599493820e2571710489ed2ee0a73b7a575 100644
--- a/atdb/taskdatabase/views.py
+++ b/atdb/taskdatabase/views.py
@@ -55,6 +55,8 @@ class TaskFilter(filters.FilterSet):
             'purge_policy': ['exact'],
             'priority': ['exact','lte','gte'],
             'resume': ['exact'],
+            # http://localhost:8000/atdb/tasks/?predecessor__isnull=True
+            'predecessor': ['isnull'],
             'predecessor__status': ['exact', 'icontains', 'in', 'startswith'],
         }