diff --git a/airflow/www/views.py b/airflow/www/views.py
index 4c3d33a6b1e05..7d8a768e324e4 100644
--- a/airflow/www/views.py
+++ b/airflow/www/views.py
@@ -258,7 +258,11 @@ def task_group_to_grid(task_item_or_group, dag, dag_runs, session):
     if isinstance(task_item_or_group, AbstractOperator):
         return {
             'id': task_item_or_group.task_id,
-            'instances': [wwwutils.get_task_summary(dr, task_item_or_group, session) for dr in dag_runs],
+            'instances': [
+                ts
+                for ts in (wwwutils.get_task_summary(dr, task_item_or_group, session) for dr in dag_runs)
+                if ts is not None
+            ],
             'label': task_item_or_group.label,
             'extra_links': task_item_or_group.extra_links,
             'is_mapped': task_item_or_group.is_mapped,