diff --git a/maya/core.py b/maya/core.py
index 35dec43..19b34e2 100644
--- a/maya/core.py
+++ b/maya/core.py
@@ -675,7 +675,7 @@ def now():
     return MayaDT(epoch=epoch)
 
 
-def when(string, timezone='UTC', prefer_past=None):
+def when(string, timezone='UTC', prefer_dates_from='current_period'):
     """"Returns a MayaDT instance for the human moment specified.
 
     Powered by dateparser. Useful for scraping websites.
@@ -693,13 +693,9 @@ def when(string, timezone='UTC', prefer_past=None):
         'TIMEZONE': timezone,
         'RETURN_AS_TIMEZONE_AWARE': True,
         'TO_TIMEZONE': 'UTC',
+        'PREFER_DATES_FROM': prefer_dates_from,
     }
 
-    if prefer_past is False:
-        settings['PREFER_DATES_FROM'] = 'future'
-    if prefer_past is True:
-        settings['PREFER_DATES_FROM'] = 'past'
-
     dt = dateparser.parse(string, settings=settings)
     if dt is None:
         raise ValueError('invalid datetime input specified.')