diff --git a/mayan/apps/common/literals.py b/mayan/apps/common/literals.py
index 8b65daf4c0..ca8bee1dcc 100644
--- a/mayan/apps/common/literals.py
+++ b/mayan/apps/common/literals.py
@@ -4,9 +4,14 @@ from django.utils.translation import ugettext_lazy as _
 
 
 DELETE_STALE_UPLOADS_INTERVAL = 60 * 10  # 10 minutes
+
+TIME_DELTA_UNIT_DAYS = 'days'
+TIME_DELTA_UNIT_HOURS = 'hours'
+TIME_DELTA_UNIT_MINUTES = 'minutes'
+
 TIME_DELTA_UNIT_CHOICES = (
-    ('days', _('Days')),
-    ('hours', _('Hours')),
-    ('minutes', _('Minutes')),
+    (TIME_DELTA_UNIT_DAYS, _('Days')),
+    (TIME_DELTA_UNIT_HOURS, _('Hours')),
+    (TIME_DELTA_UNIT_MINUTES, _('Minutes')),
 )
 UPLOAD_EXPIRATION_INTERVAL = 60 * 60 * 24 * 7  # 7 days
diff --git a/mayan/apps/documents/literals.py b/mayan/apps/documents/literals.py
index 6ca53aaab6..d32efaee0a 100644
--- a/mayan/apps/documents/literals.py
+++ b/mayan/apps/documents/literals.py
@@ -2,12 +2,14 @@ from __future__ import unicode_literals
 
 from django.utils.translation import ugettext_lazy as _
 
+from common.literals import TIME_DELTA_UNIT_DAYS
+
 CACHE_PATH = 'document_cache/'
 CHECK_DELETE_PERIOD_INTERVAL = 60
 CHECK_TRASH_PERIOD_INTERVAL = 60
 DELETE_STALE_STUBS_INTERVAL = 60 * 10  # 10 minutes
 DEFAULT_DELETE_PERIOD = 30
-DEFAULT_DELETE_TIME_UNIT = 'days'
+DEFAULT_DELETE_TIME_UNIT = TIME_DELTA_UNIT_DAYS
 DEFAULT_ZIP_FILENAME = 'document_bundle.zip'
 DOCUMENT_IMAGE_TASK_TIMEOUT = 20
 STUB_EXPIRATION_INTERVAL = 60 * 60 * 24  # 24 hours