diff --git a/lib/ransack/adapters/active_record/base.rb b/lib/ransack/adapters/active_record/base.rb
index c4ca935..6975e80 100644
--- a/lib/ransack/adapters/active_record/base.rb
+++ b/lib/ransack/adapters/active_record/base.rb
@@ -23,7 +23,8 @@ module Ransack
         end
 
         def ransack_alias(new_name, old_name)
-          self._ransack_aliases.store(new_name.to_s, old_name.to_s)
+          self._ransack_aliases = _ransack_aliases.merge new_name.to_s =>
+            old_name.to_s
         end
 
         # Ransackable_attributes, by default, returns all column names
diff --git a/lib/ransack/adapters/mongoid/base.rb b/lib/ransack/adapters/mongoid/base.rb
index a952a7c..50d4353 100644
--- a/lib/ransack/adapters/mongoid/base.rb
+++ b/lib/ransack/adapters/mongoid/base.rb
@@ -8,6 +8,10 @@ module Ransack
         extend ActiveSupport::Concern
 
         included do
+          class_attribute :_ransackers
+          class_attribute :_ransack_aliases
+          self._ransackers ||= {}
+          self._ransack_aliases ||= {}
         end
 
         class ColumnWrapper < SimpleDelegator
@@ -33,22 +37,6 @@ module Ransack
         end
 
         module ClassMethods
-          def _ransack_aliases
-            @_ransack_aliases ||= {}
-          end
-
-          def _ransack_aliases=(value)
-            @_ransack_aliases = value
-          end
-
-          def _ransackers
-            @_ransackers ||= {}
-          end
-
-          def _ransackers=(value)
-            @_ransackers = value
-          end
-
           def ransack(params = {}, options = {})
             params = params.presence || {}
             Search.new(self, params ? params.delete_if {
@@ -58,7 +46,8 @@ module Ransack
           alias_method :search, :ransack
 
           def ransack_alias(new_name, old_name)
-            self._ransack_aliases.store(new_name.to_s, old_name.to_s)
+            self._ransack_aliases = _ransack_aliases.merge new_name.to_s =>
+              old_name.to_s
           end
 
           def ransacker(name, opts = {}, &block)
diff --git a/spec/mongoid/adapters/mongoid/base_spec.rb b/spec/mongoid/adapters/mongoid/base_spec.rb
index 8702960..b2f7a6a 100644
--- a/spec/mongoid/adapters/mongoid/base_spec.rb
+++ b/spec/mongoid/adapters/mongoid/base_spec.rb
@@ -65,6 +65,27 @@ module Ransack
             s = Person.ransack(term_cont: 'nomatch')
             expect(s.result.to_a).to eq []
           end
+
+          it 'makes aliases available to subclasses' do
+            yngwie = Musician.create!(name: 'Yngwie Malmsteen')
+
+            musicians = Musician.ransack(term_cont: 'ngw').result
+            expect(musicians).to eq([yngwie])
+          end
+
+          it 'handles naming collisions gracefully' do
+            frank = Person.create!(name: 'Frank Stallone')
+
+            people = Person.ransack(term_cont: 'allon').result
+            expect(people).to eq([frank])
+
+            Class.new(Article) do
+              ransack_alias :term, :title
+            end
+
+            people = Person.ransack(term_cont: 'allon').result
+            expect(people).to eq([frank])
+          end
         end
 
         describe '#ransacker' do
diff --git a/spec/mongoid/support/schema.rb b/spec/mongoid/support/schema.rb
index 6c15768..5f6f0e9 100644
--- a/spec/mongoid/support/schema.rb
+++ b/spec/mongoid/support/schema.rb
@@ -63,6 +63,9 @@ class Person
   end
 end
 
+class Musician < Person
+end
+
 class Article
   include Mongoid::Document
 
diff --git a/spec/ransack/adapters/active_record/base_spec.rb b/spec/ransack/adapters/active_record/base_spec.rb
index 9ad9175..dc6b72e 100644
--- a/spec/ransack/adapters/active_record/base_spec.rb
+++ b/spec/ransack/adapters/active_record/base_spec.rb
@@ -190,6 +190,27 @@ module Ransack
             s = Person.ransack(daddy_eq: 'Drake')
             expect(s.result.to_a).to eq []
           end
+
+          it 'makes aliases available to subclasses' do
+            yngwie = Musician.create!(name: 'Yngwie Malmsteen')
+
+            musicians = Musician.ransack(term_cont: 'ngw').result
+            expect(musicians).to eq([yngwie])
+          end
+
+          it 'handles naming collisions gracefully' do
+            frank = Person.create!(name: 'Frank Stallone')
+
+            people = Person.ransack(term_cont: 'allon').result
+            expect(people).to eq([frank])
+
+            Class.new(Article) do
+              ransack_alias :term, :title
+            end
+
+            people = Person.ransack(term_cont: 'allon').result
+            expect(people).to eq([frank])
+          end
         end
 
         describe '#ransacker' do
diff --git a/spec/support/schema.rb b/spec/support/schema.rb
index 4600303..fe5c9b8 100644
--- a/spec/support/schema.rb
+++ b/spec/support/schema.rb
@@ -127,6 +127,9 @@ class Person < ActiveRecord::Base
   end
 end
 
+class Musician < Person
+end
+
 class Article < ActiveRecord::Base
   belongs_to :person
   has_many :comments