diff --git a/cubes/query/browser.py b/cubes/query/browser.py
index c547abaa..20d36692 100644
--- a/cubes/query/browser.py
+++ b/cubes/query/browser.py
@@ -1009,16 +1009,16 @@ def all_attributes(self):
     @property
     def natural_order(self):
         """Return a natural order for the drill-down. This order can be merged
-        with user-specified order. Returns a list of tuples:
-        (`attribute_name`, `order`)."""
+        with user-specified order. Returns a dictionary where keys are
+        attribute ref and vales are directions."""
 
-        order = []
+        order = {}
 
         for item in self.drilldown:
             for level in item.levels:
                 lvl_attr = level.order_attribute or level.key
                 lvl_order = level.order or 'asc'
-                order.append((lvl_attr, lvl_order))
+                order[lvl_attr.ref] = lvl_order
 
         return order
 
diff --git a/cubes/sql/utils.py b/cubes/sql/utils.py
index 10030c00..ddfcc872 100644
--- a/cubes/sql/utils.py
+++ b/cubes/sql/utils.py
@@ -154,7 +154,7 @@ def order_query(statement, order, natural_order=None, labels=None):
     # Collect natural order for selected columns that have no explicit
     # ordering
     for (name, column) in columns.items():
-        if name in natural_order and name not in order_by:
+        if name in natural_order and name not in final_order.keys():
             final_order[name] = order_column(column, natural_order[name])
 
     statement = statement.order_by(*final_order.values())