diff --git a/Gemfile b/Gemfile
index 933c613..fe1f9bc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,12 +13,4 @@ rails =
 
 gem 'rails', rails
 
-# Required for Rails 6.1.x with Ruby 3.1+
-if RUBY_VERSION >= '3.1'
-  gem 'net-smtp', require: false
-  gem 'net-imap', require: false
-  gem 'net-pop', require: false
-end
-
-
 gemspec
diff --git a/jsonapi-rails.gemspec b/jsonapi-rails.gemspec
index 04b8d82..24c4a45 100644
--- a/jsonapi-rails.gemspec
+++ b/jsonapi-rails.gemspec
@@ -22,7 +22,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'rails', '>= 5.0'
   spec.add_development_dependency 'sqlite3', '>= 1.3'
   spec.add_development_dependency 'rake',        '>= 11.3'
-  spec.add_development_dependency 'rspec-rails', '~> 3.5'
+  spec.add_development_dependency 'rspec-rails', '>= 4.0'
   spec.add_development_dependency 'with_model',  '~> 2.0'
   spec.add_development_dependency 'simplecov'
 end
diff --git a/spec/deserialization_spec.rb b/spec/deserialization_spec.rb
index f7a0454..20042c4 100644
--- a/spec/deserialization_spec.rb
+++ b/spec/deserialization_spec.rb
@@ -25,7 +25,8 @@ def create
     it 'makes the deserialized resource available in params' do
       post :create, params: payload
 
-      expected = { 'type' => 'users', 'name' => 'Lucas' }
+      expected = ActionController::Parameters.new('type' => 'users',
+                                                  'name' => 'Lucas')
       expect(controller.params[:user]).to eq(expected)
     end
 
@@ -54,7 +55,8 @@ def create
     it 'makes the deserialized resource available in params' do
       post :create, params: payload
 
-      expected = { 'type' => 'users', 'first_name' => 'Lucas' }
+      expected = ActionController::Parameters.new('type' => 'users',
+                                                  'first_name' => 'Lucas')
       expect(controller.params[:user]).to eq(expected)
     end
 
@@ -81,7 +83,8 @@ def create
     it 'makes the deserialized resource available in params' do
       post :create, params: payload
 
-      expected = { 'type' => 'users', 'Name' => 'Lucas' }
+      expected = ActionController::Parameters.new('type' => 'users',
+                                                  'Name' => 'Lucas')
       expect(controller.params[:user]).to eq(expected)
     end
 
diff --git a/spec/render_jsonapi_errors_spec.rb b/spec/render_jsonapi_errors_spec.rb
index 035bd2e..c91bbd4 100644
--- a/spec/render_jsonapi_errors_spec.rb
+++ b/spec/render_jsonapi_errors_spec.rb
@@ -17,7 +17,7 @@
     {
       'errors' => [
         {
-          'detail' => 'Name can\'t be blank',
+          'detail' => "Name #{I18n.t('errors.messages.blank')}",
           'title' => 'Invalid name',
           'source' => { 'pointer' => '/data/attributes/name' }
         },
@@ -64,7 +64,7 @@ def jsonapi_pointers
       def create
         errors = [
           {
-            detail: 'Name can\'t be blank',
+            detail: "Name #{I18n.t('errors.messages.blank')}",
             title: 'Invalid name',
             source: { pointer: '/data/attributes/name' }
           },