diff --git a/openerp/fields.py b/openerp/fields.py
index 635d5db10ad..464c951a757 100644
--- a/openerp/fields.py
+++ b/openerp/fields.py
@@ -1157,13 +1157,14 @@ class Monetary(Field):
     _column_currency_field = property(attrgetter('currency_field'))
     _column_group_operator = property(attrgetter('group_operator'))
 
-    def _setup_regular_base(self, model):
-        super(Monetary, self)._setup_regular_base(model)
-        if not self.currency_field:
-            self.currency_field = 'currency_id'
-
     def _setup_regular_full(self, model):
         super(Monetary, self)._setup_regular_full(model)
+        if not self.currency_field:
+            # pick a default, trying in order: 'currency_id', 'x_currency_id'
+            if 'currency_id' in model._fields:
+                self.currency_field = 'currency_id'
+            elif 'x_currency_id' in model._fields:
+                self.currency_field = 'x_currency_id'
         assert self.currency_field in model._fields, \
             "Field %s with unknown currency_field %r" % (self, self.currency_field)