diff --git a/.rubocop.yml b/.rubocop.yml
index dc6c678..489ee3f 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -3,7 +3,7 @@ inherit_from:
 
 AllCops:
   TargetRubyVersion: 2.2
-  TargetRailsVersion: 4.2
+  TargetRailsVersion: 5.1
 
 Rails:
   Enabled: true
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index e55f38c..11b0a87 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,3 +1,11 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config`
+# on 2018-01-07 04:22:08 +0100 using RuboCop version 0.52.1.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
 # Offense count: 2
 Lint/HandleExceptions:
   Exclude:
@@ -8,12 +16,6 @@ Lint/RescueException:
   Exclude:
     - 'lib/foreman_xen/vnc_tunnel.rb'
 
-# Offense count: 9
-Lint/RescueWithoutErrorClass:
-  Exclude:
-    - 'app/models/foreman_xen/xenserver.rb'
-    - 'lib/foreman_xen/engine.rb'
-
 # Offense count: 2
 # Cop supports --auto-correct.
 # Configuration parameters: IgnoreEmptyBlocks, AllowUnusedKeywordArguments.
@@ -71,3 +73,12 @@ Metrics/ParameterLists:
 # Offense count: 4
 Metrics/PerceivedComplexity:
   Max: 13
+
+# Offense count: 9
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle.
+# SupportedStyles: implicit, explicit
+Style/RescueStandardError:
+  Exclude:
+    - 'app/models/foreman_xen/xenserver.rb'
+    - 'lib/foreman_xen/engine.rb'
diff --git a/.travis.yml b/.travis.yml
index d187e48..8c3d2f9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ rvm:
   - 2.2.3
   - 2.3.1
   - 2.4.2
+  - 2.5.0
 before_install:
   - gem update --remote bundler
 install:
diff --git a/Gemfile b/Gemfile
index 6824aa9..ee415dd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,5 +2,4 @@ source 'https://rubygems.org'
 
 gemspec
 
-gem 'nokogiri', '< 1.7', require: false if RUBY_VERSION.start_with? '2.0.'
-gem 'rubocop', '~> 0.51.0', require: false
+gem 'rubocop', '~> 0.52.1', require: false
diff --git a/app/controllers/foreman_xen/snapshots_controller.rb b/app/controllers/foreman_xen/snapshots_controller.rb
index 030631c..c0ab7d6 100644
--- a/app/controllers/foreman_xen/snapshots_controller.rb
+++ b/app/controllers/foreman_xen/snapshots_controller.rb
@@ -96,9 +96,7 @@ def new
     def create
       id   = params[:id]
       name = params[:name]
-      if name.nil? || name == ''
-        process_error(:error_msg => 'You must supply a name.')
-      end
+      process_error(:error_msg => 'You must supply a name.') if name.nil? || name == ''
       @host = get_host_by_id(id)
       if !@host.nil?
         @compute_resource = get_compute_resource_by_host_id(id)
diff --git a/app/helpers/xen_compute_helper.rb b/app/helpers/xen_compute_helper.rb
index 490f575..7d62ad2 100644
--- a/app/helpers/xen_compute_helper.rb
+++ b/app/helpers/xen_compute_helper.rb
@@ -55,9 +55,7 @@ def compute_resource_controller_attribute_map(params, compute_resource)
     elsif params && params['host'] && params['host']['compute_profile_id']
       compute_attributes = compute_resource.compute_profile_attributes_for(params['host']['compute_profile_id'])
     end
-    if compute_attributes
-      attribute_map = filter_compute_attributes(attribute_map, compute_attributes)
-    end
+    attribute_map = filter_compute_attributes(attribute_map, compute_attributes) if compute_attributes
     attribute_map
   end
 
@@ -78,9 +76,7 @@ def filter_compute_attributes(attribute_map, compute_attributes)
       attribute_map[:volume_size]     = compute_attributes['VBDs']['physical_size']
       attribute_map[:volume_selected] = compute_attributes['VBDs']['sr_uuid']
     end
-    if compute_attributes['VIFs']
-      attribute_map[:network_selected] = compute_attributes['VIFs']['print']
-    end
+    attribute_map[:network_selected] = compute_attributes['VIFs']['print'] if compute_attributes['VIFs']
     attribute_map[:template_selected_custom]  = compute_attributes['custom_template_name']
     attribute_map[:template_selected_builtin] = compute_attributes['builtin_template_name']
     attribute_map[:cpu_count]                 = compute_attributes['vcpus_max']