diff --git a/oxdata/lookup/tasks.py b/oxdata/lookup/tasks.py
index ec3f791..8f2a0a0 100644
--- a/oxdata/lookup/tasks.py
+++ b/oxdata/lookup/tasks.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # vi:si:et:sw=4:sts=4:ts=4
-from datetime import timedelta
+from datetime import timedelta, datetime
 
 from celery.decorators import task, periodic_task
 
@@ -11,8 +11,9 @@ import poster.models
 
 @periodic_task(run_every=timedelta(days=1))
 def cronjob(**kwargs):
+    before_import = datetime.now()
     cache.getIds()
-    for p in poster.models.PosterCache.objects.filter(image='', failed=False):
+    for p in poster.models.PosterCache.objects.filter(image='', failed=False, created__gt=before_import):
         p.get()
 
 @task(ignore_resulsts=True, queue='default')