diff --git a/app/models/report/group_by/base.rb b/app/models/report/group_by/base.rb
index 6d974e8827..0d90117bd8 100644
--- a/app/models/report/group_by/base.rb
+++ b/app/models/report/group_by/base.rb
@@ -38,7 +38,7 @@ class Report::GroupBy
     end
 
     def aggregation_mixin
-      sql_aggregation? ? SqlAggregation : RubyAggregation
+      sql_aggregation? ? engine::GroupBy::SqlAggregation : engine::GroupBy::RubyAggregation
     end
 
     def initialize(child = nil, optios = {})