diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index 86ff423..3531ec2 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -22,13 +22,13 @@ module Ransack
 
         def type_for(attr)
           return nil unless attr && attr.valid?
-          name        = attr.arel_attribute.name.to_s
-          table       = attr.arel_attribute.relation.table_name
-          connection  = attr.klass.connection
-          unless connection.table_exists?(table)
-            raise "No table named #{table} exists"
+          name         = attr.arel_attribute.name.to_s
+          table        = attr.arel_attribute.relation.table_name
+          schema_cache = @engine.connection.schema_cache
+          unless schema_cache.table_exists?(table)
+            raise "No table named #{table} exists."
           end
-          connection.schema_cache.columns_hash(table)[name].type
+          schema_cache.columns_hash(table)[name].type
         end
 
         def evaluate(search, opts = {})