diff --git a/Gemfile b/Gemfile
index db355118..bcea423f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -140,6 +140,7 @@ group :test do
   gem 'timecop'
   gem 'turnip'
   gem 'webmock'
+  gem "rails-controller-testing"
   #gem 'rails-controller-testing'
   #gem 'rb-fsevent', require: false #if RUBY_PLATFORM =~ /darwin/i
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 3802db06..380f1d98 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -445,6 +445,10 @@ GEM
       activesupport (= 8.0.2.1)
       bundler (>= 1.15.0)
       railties (= 8.0.2.1)
+    rails-controller-testing (1.0.5)
+      actionpack (>= 5.0.1.rc1)
+      actionview (>= 5.0.1.rc1)
+      activesupport (>= 5.0.1.rc1)
     rails-dom-testing (2.3.0)
       activesupport (>= 5.0.0)
       minitest
@@ -640,6 +644,7 @@ DEPENDENCIES
   puma (>= 5.0)
   rack-cors
   rails (~> 8.0.2.1)
+  rails-controller-testing
   rqrcode
   rspec-its
   rspec-rails
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 8493844a..801e57cd 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -125,9 +125,9 @@ private
   end
   alias json_notice js_notice
 
-  def show_404(options = {})
+  def show_404(error)
     respond_to do |format|
-      format.html { render 'dashboard/404', options.reverse_merge(layout: true, status: 404)}
+      format.html { render 'dashboard/404', {layout: true, status: 404} }
       format.json { render json: {ok: false}, status: 404 }
     end
   end
@@ -138,7 +138,7 @@ private
     if obj.is_a?(SimplyStored::Couch)
       if obj.errors.present?
         #json_api_errors = obj.errors.details.map{|key, ers| {id: key, status: '422', title: ers.map{|e| e[:error].to_s}.join(', '), source: {parameter: key}}}
-        json_api_errors = obj.errors.map{|error| {id: error.attribute, status: '422', title: error.message}}
+        json_api_errors = obj.errors.map{|error| {id: error.attribute.to_s, status: '422', title: error.message}}
         options.reverse_merge(json: {errors: json_api_errors, ok: false}, status: :unprocessable_entity)
       else
         options.reverse_merge(json: obj)
diff --git a/app/controllers/suppliers/products_controller.rb b/app/controllers/suppliers/products_controller.rb
index 6635ac90..d667463f 100644
--- a/app/controllers/suppliers/products_controller.rb
+++ b/app/controllers/suppliers/products_controller.rb
@@ -19,7 +19,6 @@ module Suppliers
     # GET /products/1
     # GET /products/1.json
     def show
-
       respond_to do |format|
         format.html # show.html.erb
         format.json { render json: @product }
diff --git a/config/initializers/custom_form_builder.rb b/config/initializers/custom_form_builder.rb
index 24234b94..c1f3409f 100644
--- a/config/initializers/custom_form_builder.rb
+++ b/config/initializers/custom_form_builder.rb
@@ -3,7 +3,7 @@ class CustomFormBuilder < ActionView::Helpers::FormBuilder
     t = @template
     elements = []
     elements << submit(nil, class: 'form-action-submit')
-    plural_subject = object.class.name.underscore.pluralize
+    plural_subject = object.class.name.underscore.pluralize.to_sym
     elements << t.link_to(
       t.content_tag(:span, nil, data: {t: 'helpers.links.cancel'}),
       [:suppliers, plural_subject],
diff --git a/spec/controllers/suppliers/products_controller_spec.rb b/spec/controllers/suppliers/products_controller_spec.rb
index edbda994..70269a90 100644
--- a/spec/controllers/suppliers/products_controller_spec.rb
+++ b/spec/controllers/suppliers/products_controller_spec.rb
@@ -17,13 +17,13 @@ describe Suppliers::ProductsController, type: :controller do
   describe "GET #show" do
     it "assigns the requested product to @product" do
       product = create :product, supplier: @supplier
-      get :show, id: product
+      get :show, params: {id: product}
       assigns(:product).should eq(product)
     end
 
     it "should not display a product of another supplier" do
       product = create :product
-      get :show, id: product
+      get :show, params: {id: product}
       expect(response.status).to eq 404
     end
   end
@@ -39,18 +39,18 @@ describe Suppliers::ProductsController, type: :controller do
     context "with valid attributes" do
       it "creates a new product" do
         expect{
-          post :create, product: valid_attributes
+          post :create, params: {product: valid_attributes}
         }.to change(Product, :count).by(1)
       end
 
       it "redirects to the new product" do
-        post :create, product: valid_attributes
+        post :create, params: {product: valid_attributes}
         response.should redirect_to [:suppliers, :products]
       end
 
       it "should not be possible to create a product for another supplier" do
         supplier2 = create :supplier
-        post :create, product: valid_attributes.merge(name: 'Trying to hack', supplier_id: supplier2.id)
+        post :create, params: {product: valid_attributes.merge(name: 'Trying to hack', supplier_id: supplier2.id)}
         expect( Product.find_by_name('Trying to hack').supplier_id ).to eq @supplier.id
       end
     end
@@ -58,12 +58,12 @@ describe Suppliers::ProductsController, type: :controller do
     context "with invalid attributes" do
       it "does not save the new product" do
         expect{
-          post :create, product: invalid_attributes
+          post :create, params: {product: invalid_attributes}
         }.to_not change(Product, :count)
       end
 
       it 'returns an error object' do
-        post :create, format: :json, product: invalid_attributes
+        post :create, params: {format: :json, product: invalid_attributes}
         expect( JSON.parse(response.body)['errors'] ).to be_present
       end
     end
@@ -76,26 +76,26 @@ describe Suppliers::ProductsController, type: :controller do
 
     context "valid attributes" do
       it "located the requested product" do
-        put :update, id: @product, product: valid_attributes
+        put :update, params: {id: @product, product: valid_attributes}
         @product.reload
         assigns(:product).should eq(@product)
       end
 
       it "changes @product's attributes" do
-        put :update, id: @product, product: valid_attributes.merge(name: "ChangedByTest")
+        put :update, params: {id: @product, product: valid_attributes.merge(name: "ChangedByTest")}
         @product.reload
         @product.name.should eq("ChangedByTest")
       end
 
       it "should not be possible to update a product to another supplier" do
         supplier2 = create :supplier
-        put :update, id: @product, product: valid_attributes.merge(name: "Trying to hack", supplier_id: supplier2.id)
+        put :update, params: {id: @product, product: valid_attributes.merge(name: "Trying to hack", supplier_id: supplier2.id)}
         expect( Product.find_by_name('Trying to hack' ).supplier_id ).to eq @supplier.id
       end
 
       it "should not be possible to update a product of another supplier" do
         product = create :product, name: 'Other supplier product'
-        put :update, id: product, product: {name: "Trying to hack"}
+        put :update, params: {id: product, product: {name: "Trying to hack"}}
         product.reload
         expect( product.name ).to eq 'Other supplier product'
       end
@@ -103,7 +103,7 @@ describe Suppliers::ProductsController, type: :controller do
 
     context "with invalid attributes" do
       it "returns an error response" do
-        put :update, id: @product, format: :json, product: invalid_attributes
+        put :update, params: {id: @product, format: :json, product: invalid_attributes}
         expect( JSON.parse( response.body )['errors']).to be_present
       end
     end
@@ -116,14 +116,14 @@ describe Suppliers::ProductsController, type: :controller do
 
     it "deletes the product" do
       expect{
-        delete :destroy, id: @product
+        delete :destroy, params: {id: @product}
       }.to change(Product, :count).by(-1)
     end
 
     it "should not be possible to delete a product of another supplier" do
       product = create :product
       expect{
-        delete :destroy, id: product.id
+        delete :destroy, params: {id: product.id}
       }.to_not change(Product, :count)
     end
   end