diff --git a/iceprod/scheduled_tasks/update_task_priority.py b/iceprod/scheduled_tasks/update_task_priority.py
index fe6be2ca..a289a193 100644
--- a/iceprod/scheduled_tasks/update_task_priority.py
+++ b/iceprod/scheduled_tasks/update_task_priority.py
@@ -22,7 +22,8 @@ async def run(rest_client, dataset_id=None, status=None, debug=False):
         status (list): list of task statuses to update
         debug (bool): debug flag to propagate exceptions
     """
-    assert status
+    if not status:
+        status = ['idle', 'waiting']
     prio = Priority(rest_client)
     try:
         args = {
diff --git a/iceprod/server/priority.py b/iceprod/server/priority.py
index 7005464f..901596c8 100644
--- a/iceprod/server/priority.py
+++ b/iceprod/server/priority.py
@@ -235,12 +235,12 @@ async def get_task_prio(self, dataset_id, task_id):
         tasks_per_job = dataset['tasks_submitted'] / dataset['jobs_submitted']
 
         # bias towards finishing jobs
-        priority += (1. * task['task_index'] / tasks_per_job) / 10.
+        priority += (1. * task['task_index'] / tasks_per_job) / 5.
         logger.info(f'{dataset_id}.{task_id} after finishing jobs adjustment: {priority}')
 
-        # bias towards first jobs in dataset
-        priority += (1. * (dataset['jobs_submitted'] - task['job_index']) / dataset['jobs_submitted']) / 100.
-        logger.info(f'{dataset_id}.{task_id} after first jobs adjustment: {priority}')
+        # spread out job priorities to allow dataset balancing
+        priority -= (1. - (dataset['jobs_submitted'] - task['job_index']) / dataset['jobs_submitted']) / 5.
+        logger.info(f'{dataset_id}.{task_id} after job index adjustment: {priority}')
 
         # boost towards first 100 jobs (or small datasets)
         if task['job_index'] < 100: