diff --git a/app/controllers/spree/admin/bookkeeping_documents_controller.rb b/app/controllers/spree/admin/bookkeeping_documents_controller.rb
index fd074f83..5f8ef9a6 100644
--- a/app/controllers/spree/admin/bookkeeping_documents_controller.rb
+++ b/app/controllers/spree/admin/bookkeeping_documents_controller.rb
@@ -8,7 +8,10 @@ class BookkeepingDocumentsController < ResourceController
       def show
         respond_with(@bookkeeping_document) do |format|
           format.pdf do
-            send_data @bookkeeping_document.pdf, type: 'application/pdf', disposition: 'inline'
+            send_data @bookkeeping_document.pdf,
+                      type: 'application/pdf',
+                      disposition: 'inline',
+                      filename: pdf_filename
           end
         end
       end
@@ -39,6 +42,10 @@ def order_focused?
       def load_order
         @order = Spree::Order.find_by(number: params[:order_id])
       end
+
+      def pdf_filename
+        "#{@bookkeeping_document.template}_#{@bookkeeping_document.number}_#{@bookkeeping_document.printable.bill_address.firstname}_#{@bookkeeping_document.printable.completed_at.to_i}.pdf"
+      end
     end
   end
 end
diff --git a/app/models/spree/bookkeeping_document.rb b/app/models/spree/bookkeeping_document.rb
index bbe3c76e..b839920d 100644
--- a/app/models/spree/bookkeeping_document.rb
+++ b/app/models/spree/bookkeeping_document.rb
@@ -8,6 +8,10 @@ class BookkeepingDocument < ActiveRecord::Base
       :number
     ]
 
+    def self.ransackable_attributes(auth_object = nil)
+      ["created_at", "email", "firstname", "id", "id_value", "lastname", "number", "printable_id", "printable_type", "template", "total", "updated_at"]
+    end
+
     # Spree::BookkeepingDocument cares about creating PDFs. Whenever it needs to know
     # anything about the document to send to the view, it asks a view object.
     #
@@ -108,7 +112,8 @@ def storage_path
     #
     def render_pdf
       ApplicationController.render(
-        template: "#{template_name}.pdf.prawn",
+        template: template_name,
+        formats: [:pdf],
         assigns: { doc: self }
       )
     end
diff --git a/app/models/spree_print_invoice/admin/main_menu/print_invoice_builder.rb b/app/models/spree_print_invoice/admin/main_menu/print_invoice_builder.rb
new file mode 100644
index 00000000..5bd633eb
--- /dev/null
+++ b/app/models/spree_print_invoice/admin/main_menu/print_invoice_builder.rb
@@ -0,0 +1,30 @@
+module SpreePrintInvoice
+  module Admin
+    module MainMenu
+      class PrintInvoiceBuilder
+        include ::Spree::Core::Engine.routes.url_helpers
+
+        def build
+          items = [
+            ::Spree::Admin::MainMenu::ItemBuilder.new('invoices', ::Spree::Core::Engine.routes.url_helpers.admin_bookkeeping_documents_path(q: { template_eq: 'invoice' })).
+              with_label_translation_key('admin.tab.invoices').
+              with_manage_ability_check(::Spree::BookkeepingDocument).
+              with_match_path('/bookkeeping_documents?q%5Btemplate_eq%5D=invoice').
+              build,
+            ::Spree::Admin::MainMenu::ItemBuilder.new('packaging_slips', ::Spree::Core::Engine.routes.url_helpers.admin_bookkeeping_documents_path(q: { template_eq: 'packaging_slip' })).
+              with_label_translation_key('admin.tab.packaging_slips').
+              with_manage_ability_check(::Spree::BookkeepingDocument).
+              with_match_path('/bookkeeping_documents?q%5Btemplate_eq%5D=packaging_slip').
+              build
+          ]
+
+          ::Spree::Admin::MainMenu::SectionBuilder.new('documents', 'file.svg').
+              with_manage_ability_check(::Spree::BookkeepingDocument).
+              with_label_translation_key('admin.documents').
+              with_items(items).
+              build
+        end
+      end
+    end
+  end
+end
diff --git a/app/models/spree/order_decorator.rb b/app/models/spree_print_invoice/order_decorator.rb
similarity index 89%
rename from app/models/spree/order_decorator.rb
rename to app/models/spree_print_invoice/order_decorator.rb
index e6bed8d1..bc5e65cb 100644
--- a/app/models/spree/order_decorator.rb
+++ b/app/models/spree_print_invoice/order_decorator.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-module Spree
+module SpreePrintInvoice
   module OrderDecorator
     def self.prepended(base)
       base.has_many :bookkeeping_documents, as: :printable, dependent: :destroy
@@ -42,9 +42,11 @@ def pdf_storage_path(template)
     end
 
     def invoice_for_order
+      return if bookkeeping_documents.exists?(template: 'invoice') && bookkeeping_documents.exists?(template: 'packaging_slip')
       bookkeeping_documents.create(template: 'invoice')
       bookkeeping_documents.create(template: 'packaging_slip')
     end
   end
 end
-::Spree::Order.prepend Spree::OrderDecorator
\ No newline at end of file
+
+::Spree::Order.prepend SpreePrintInvoice::OrderDecorator
diff --git a/app/overrides/add_documents_to_main_navigation.rb b/app/overrides/add_documents_to_main_navigation.rb
deleted file mode 100644
index cc514835..00000000
--- a/app/overrides/add_documents_to_main_navigation.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-# frozen_string_literal: true
-
-if Spree.version.to_f < 4.0
-  Deface::Override.new(
-    virtual_path: 'spree/layouts/admin',
-    insert_bottom: '#main-sidebar',
-    partial: 'spree/admin/shared/menu/documents_tab',
-    name: 'documents_tab'
-  )
-else
-  Deface::Override.new(
-    virtual_path: 'spree/admin/shared/_main_menu',
-    insert_bottom: 'nav',
-    partial: 'spree/admin/shared/menu/documents_tab',
-    name: 'documents_tab'
-  )
-end
diff --git a/app/overrides/add_print_invoice_links_to_admin_order_tabs.rb b/app/overrides/add_print_invoice_links_to_admin_order_tabs.rb
deleted file mode 100644
index cf7382df..00000000
--- a/app/overrides/add_print_invoice_links_to_admin_order_tabs.rb
+++ /dev/null
@@ -1,8 +0,0 @@
-# frozen_string_literal: true
-
-Deface::Override.new(
-  virtual_path: 'spree/admin/shared/_order_tabs',
-  name: 'print_invoice_order_tab_links',
-  insert_bottom: '[data-hook="admin_order_tabs"]',
-  partial: 'spree/admin/orders/print_invoice_order_tab_links'
-)
diff --git a/app/overrides/add_print_invoice_to_admin_configuration_sidebar.rb b/app/overrides/add_print_invoice_to_admin_configuration_sidebar.rb
deleted file mode 100644
index 9c143549..00000000
--- a/app/overrides/add_print_invoice_to_admin_configuration_sidebar.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-# frozen_string_literal: true
-
-Deface::Override.new(
-  virtual_path: 'spree/admin/shared/sub_menu/_configuration',
-  name: 'print_invoice_admin_configurations_menu',
-  insert_bottom: '[data-hook="admin_configurations_sidebar_menu"]',
-  text: '<%= configurations_sidebar_menu_item Spree.t(:settings, scope: :print_invoice),
-                      spree.edit_admin_print_invoice_settings_path %>'
-)
diff --git a/app/views/spree/admin/orders/_print_invoice_order_tab_links.html.erb b/app/views/spree/admin/orders/_print_invoice_order_tab_links.html.erb
deleted file mode 100755
index ccc6a9d2..00000000
--- a/app/views/spree/admin/orders/_print_invoice_order_tab_links.html.erb
+++ /dev/null
@@ -1,12 +0,0 @@
-<% if can? :show, Spree::Order %>
-  <% if @order && @order.completed_at? %>
-    <li data-hook="admin_order_tabs_bookkeeping_documents">
-      <%=
-        link_to_with_icon 'file.svg',
-                          Spree.t(:documents, scope: [:print_invoice]),
-                          spree.admin_order_bookkeeping_documents_path(@order),
-                          { class: "nav-link #{'active' if current == :documents}" }
-      %>
-    </li>
-  <% end %>
-<% end %>
\ No newline at end of file
diff --git a/app/views/spree/admin/shared/menu/_documents_tab.html.erb b/app/views/spree/admin/shared/menu/_documents_tab.html.erb
deleted file mode 100644
index 7b8556fa..00000000
--- a/app/views/spree/admin/shared/menu/_documents_tab.html.erb
+++ /dev/null
@@ -1,3 +0,0 @@
-<ul class="nav nav-sidebar border-bottom">
-  <%= main_menu_tree Spree.t(:documents, scope: [:print_invoice]), url: '#sidebar-documents', icon: 'file.svg', sub_menu: 'documents_sub_menu' %>
-</ul>
diff --git a/app/views/spree/admin/shared/sub_menu/_documents_sub_menu.html.erb b/app/views/spree/admin/shared/sub_menu/_documents_sub_menu.html.erb
deleted file mode 100644
index 0a7878b6..00000000
--- a/app/views/spree/admin/shared/sub_menu/_documents_sub_menu.html.erb
+++ /dev/null
@@ -1,4 +0,0 @@
-<ul id="sidebar-documents" class="border-top bg-white collapse nav nav-pills nav-stacked" data-hook="admin_documents_sub_tabs">
-  <%= tab :invoices, url: spree.admin_bookkeeping_documents_path(q: { template_eq: 'invoice' }) %>
-  <%= tab :packaging_slips, url: spree.admin_bookkeeping_documents_path(q: { template_eq: 'packaging_slip' }) %>
-</ul>
diff --git a/app/views/spree/printables/shared/_header.pdf.prawn b/app/views/spree/printables/shared/_header.pdf.prawn
index 53d8af04..14bb7f61 100644
--- a/app/views/spree/printables/shared/_header.pdf.prawn
+++ b/app/views/spree/printables/shared/_header.pdf.prawn
@@ -1,6 +1,6 @@
 im = (Rails.application.assets || ::Sprockets::Railtie.build_environment(Rails.application)).find_asset(Spree::PrintInvoice::Config[:logo_path])
 
-if im && File.exist?(im.pathname)
+if im && File.exist?(im.filename)
   pdf.image im.filename, vposition: :top, height: 40, scale: Spree::PrintInvoice::Config[:logo_scale]
 end
 
@@ -11,4 +11,4 @@ pdf.grid([0,3], [1,4]).bounding_box do
   pdf.text Spree.t(:invoice_number, scope: :print_invoice, number: printable.number), align: :right
   pdf.move_down 2
   pdf.text Spree.t(:invoice_date, scope: :print_invoice, date: I18n.l(printable.date)), align: :right
-end
+end
\ No newline at end of file
diff --git a/config/initializers/print_invoice.rb b/config/initializers/print_invoice.rb
new file mode 100644
index 00000000..6a235c4f
--- /dev/null
+++ b/config/initializers/print_invoice.rb
@@ -0,0 +1,18 @@
+Rails.application.config.after_initialize do
+  if Spree::Core::Engine.backend_available?
+    Rails.application.config.spree_backend.main_menu.insert_after('dashboard', ::SpreePrintInvoice::Admin::MainMenu::PrintInvoiceBuilder.new.build)
+
+    Rails.application.config.spree_backend.tabs[:order].add(
+        ::Spree::Admin::Tabs::TabBuilder.new(::Spree.t(:documents, scope: [:print_invoice]), ->(resource) { ::Spree::Core::Engine.routes.url_helpers.admin_order_bookkeeping_documents_path(resource) }).
+          with_icon_key('file.svg').
+          with_active_check.
+          build
+      )
+
+     Rails.application.config.spree_backend.main_menu.add_to_section('settings',
+      ::Spree::Admin::MainMenu::ItemBuilder.new('print_invoice.settings', ::Spree::Core::Engine.routes.url_helpers.edit_admin_print_invoice_settings_path).
+        with_manage_ability_check(::Spree::BookkeepingDocument).
+        build
+      )
+  end
+end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 112c5070..77a1ccd6 100755
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -1,6 +1,10 @@
 ---
 en:
   spree:
+    printable_number: Printable Number
+    bookkeeping_documents: Bookkeeping Documents
+    print_invoice_settings: Print Invoice Settings
+    documents: Documents
     admin:
       tab:
         invoices: Invoices
diff --git a/lib/spree_print_invoice/engine.rb b/lib/spree_print_invoice/engine.rb
index 1ceb6c29..f0e931a9 100644
--- a/lib/spree_print_invoice/engine.rb
+++ b/lib/spree_print_invoice/engine.rb
@@ -6,7 +6,7 @@ class Engine < Rails::Engine
 
     config.autoload_paths += %W(#{config.root}/lib)
 
-    initializer 'spree.print_invoice.preferences', before: :load_config_initializers do
+    config.after_initialize do
       Spree::PrintInvoice::Config = Spree::PrintInvoiceSetting.new
     end
 
diff --git a/spree-print-invoice.gemspec b/spree-print-invoice.gemspec
index 07157683..d456f7b0 100755
--- a/spree-print-invoice.gemspec
+++ b/spree-print-invoice.gemspec
@@ -22,8 +22,8 @@ Gem::Specification.new do |s|
   s.require_path = 'lib'
   s.requirements << 'none'
 
-  s.add_runtime_dependency 'prawn-rails', '~> 1.3'
-  s.add_runtime_dependency 'spree_core', '>= 3.1.0', '< 5.0'
+  s.add_runtime_dependency 'prawn-rails', '~> 1.4.2'
+  s.add_runtime_dependency 'spree_core', '>= 4.8.0', '< 5.0'
   s.add_runtime_dependency 'spree_extension'
 
   s.add_development_dependency 'capybara'