diff --git a/parsl/monitoring/visualization/plots/default/workflow_plots.py b/parsl/monitoring/visualization/plots/default/workflow_plots.py
index ac5ae47285..2c98d59081 100644
--- a/parsl/monitoring/visualization/plots/default/workflow_plots.py
+++ b/parsl/monitoring/visualization/plots/default/workflow_plots.py
@@ -27,6 +27,9 @@
 
 def task_gantt_plot(df_task, df_status, time_completed=None):
 
+    if df_task.empty:
+        return None
+
     # if the workflow is not recorded as completed, then assume
     # that tasks should continue in their last state until now,
     # rather than the workflow end time.