diff --git a/app/controllers/spree/admin/products_controller_decorator.rb b/app/controllers/spree/admin/products_controller_decorator.rb
index 5acbc71..17c3b73 100644
--- a/app/controllers/spree/admin/products_controller_decorator.rb
+++ b/app/controllers/spree/admin/products_controller_decorator.rb
@@ -2,11 +2,11 @@
   update.before :set_stores
 
   private
+
   def set_stores
     # Remove all store associations if store data is being passed and no stores are selected
     if params[:update_store_ids] && !params[:product].key?(:store_ids)
       @product.stores.clear
     end
   end
-
-end
+end if SpreeMultiDomain::Engine.admin_available?
diff --git a/app/controllers/spree/api/line_items_controller_decorator.rb b/app/controllers/spree/api/line_items_controller_decorator.rb
index de1988d..d333bf8 100644
--- a/app/controllers/spree/api/line_items_controller_decorator.rb
+++ b/app/controllers/spree/api/line_items_controller_decorator.rb
@@ -1 +1,3 @@
-Spree::Api::LineItemsController.include SpreeMultiDomain::CreateLineItemSupport
+if SpreeMultiDomain::Engine.api_available?
+  Spree::Api::LineItemsController.include(SpreeMultiDomain::CreateLineItemSupport)
+end
diff --git a/app/controllers/spree/api/products_controller_decorator.rb b/app/controllers/spree/api/products_controller_decorator.rb
index 81c1476..20443c6 100644
--- a/app/controllers/spree/api/products_controller_decorator.rb
+++ b/app/controllers/spree/api/products_controller_decorator.rb
@@ -1 +1,3 @@
-Spree::Api::ProductsController.include(SpreeMultiDomain::ShowProductSupport)
+if SpreeMultiDomain::Engine.api_available?
+  Spree::Api::ProductsController.include(SpreeMultiDomain::ShowProductSupport)
+end
diff --git a/app/controllers/spree/api/shipments_controller_decorator.rb b/app/controllers/spree/api/shipments_controller_decorator.rb
index 3b70f0f..e35ebd5 100644
--- a/app/controllers/spree/api/shipments_controller_decorator.rb
+++ b/app/controllers/spree/api/shipments_controller_decorator.rb
@@ -13,5 +13,7 @@ def mine_with_store_scope
   end
 end
 
-Spree::Api::ShipmentsController.include SpreeMultiStore::Api::ShipmentsControllerDecorator
-Spree::Api::ShipmentsController.include SpreeMultiDomain::CreateLineItemSupport
+if SpreeMultiDomain::Engine.api_available?
+  Spree::Api::ShipmentsController.include(SpreeMultiStore::Api::ShipmentsControllerDecorator)
+  Spree::Api::ShipmentsController.include(SpreeMultiDomain::CreateLineItemSupport)
+end
diff --git a/app/controllers/spree/home_controller_decorator.rb b/app/controllers/spree/home_controller_decorator.rb
index 0dee1c8..c846326 100644
--- a/app/controllers/spree/home_controller_decorator.rb
+++ b/app/controllers/spree/home_controller_decorator.rb
@@ -4,4 +4,4 @@ def index
     @products = @searcher.retrieve_products
     @taxonomies = get_taxonomies
   end
-end
\ No newline at end of file
+end if SpreeMultiDomain::Engine.frontend_available?
diff --git a/app/controllers/spree/products_controller_decorator.rb b/app/controllers/spree/products_controller_decorator.rb
index e3b8bda..17c02a5 100644
--- a/app/controllers/spree/products_controller_decorator.rb
+++ b/app/controllers/spree/products_controller_decorator.rb
@@ -1 +1,3 @@
-Spree::ProductsController.include(SpreeMultiDomain::ShowProductSupport)
+if SpreeMultiDomain::Engine.frontend_available?
+  Spree::ProductsController.include(SpreeMultiDomain::ShowProductSupport)
+end
diff --git a/app/controllers/spree/taxons_controller_decorator.rb b/app/controllers/spree/taxons_controller_decorator.rb
index bcb22ad..c8b3285 100644
--- a/app/controllers/spree/taxons_controller_decorator.rb
+++ b/app/controllers/spree/taxons_controller_decorator.rb
@@ -7,4 +7,4 @@ def show
     @products = @searcher.retrieve_products
     @taxonomies = get_taxonomies
   end
-end
\ No newline at end of file
+end if SpreeMultiDomain::Engine.frontend_available?
diff --git a/lib/spree_multi_domain/engine.rb b/lib/spree_multi_domain/engine.rb
index 6e6cc2c..4fd89fc 100644
--- a/lib/spree_multi_domain/engine.rb
+++ b/lib/spree_multi_domain/engine.rb
@@ -4,15 +4,29 @@ class Engine < Rails::Engine
 
     config.autoload_paths += %W(#{config.root}/lib)
 
-    def self.activate
-      ['app', 'lib'].each do |dir|
-        Dir.glob(File.join(File.dirname(__FILE__), "../../#{dir}/**/*_decorator*.rb")) do |c|
-          Rails.application.config.cache_classes ? require(c) : load(c)
+    class << self
+      def activate
+        ['app', 'lib'].each do |dir|
+          Dir.glob(File.join(File.dirname(__FILE__), "../../#{dir}/**/*_decorator*.rb")) do |c|
+            Rails.application.config.cache_classes ? require(c) : load(c)
+          end
         end
+
+        Spree::Config.searcher_class = Spree::Search::MultiDomain
+        ApplicationController.send :include, SpreeMultiDomain::MultiDomainHelpers
+      end
+
+      def admin_available?
+        const_defined?('Spree::Backend::Engine')
       end
 
-      Spree::Config.searcher_class = Spree::Search::MultiDomain
-      ApplicationController.send :include, SpreeMultiDomain::MultiDomainHelpers
+      def api_available?
+        const_defined?('Spree::Api::Engine')
+      end
+
+      def frontend_available?
+        const_defined?('Spree::Frontend::Engine')
+      end
     end
 
     config.to_prepare &method(:activate).to_proc