diff --git a/CHANGELOG.md b/CHANGELOG.md
index 38561c43907e..0541a7173b2f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,8 @@
 
 ### New features
 
-* [#491](https://github.com/bbatsov/rubocop/issues/491) - New cop `MethodCalledOnDoEndBlock` keep track of methods called on `do`...`end` blocks.
+* [#491](https://github.com/bbatsov/rubocop/issues/491) - New cop `MethodCalledOnDoEndBlock` keeps track of methods called on `do`...`end` blocks.
+* [#456](https://github.com/bbatsov/rubocop/issues/456) - New configuration parameter `AllCops`/`RunRailsCops` can be set to `true` for a project, removing the need to give the `-R`/`--rails` option with every invocation of `rubocop`.
 
 ### Bugs fixed
 
diff --git a/config/default.yml b/config/default.yml
index 585360f64d52..bc58dbe87e94 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -12,6 +12,9 @@ AllCops:
     - '**/*.gemspec'
     - '**/Rakefile'
   Excludes: []
+  # By default, the rails cops are not run. Override in project or home
+  # directory .rubocop.yml files, or by giving the -R/--rails option.
+  RunRailsCops: false
 
 LineLength:
   Max: 79
diff --git a/lib/rubocop/cli.rb b/lib/rubocop/cli.rb
index 7d44621a8f78..56a87d53a97c 100644
--- a/lib/rubocop/cli.rb
+++ b/lib/rubocop/cli.rb
@@ -63,7 +63,7 @@ def run(args = ARGV)
       return 1
     end
 
-    def mobilized_cop_classes
+    def mobilized_cop_classes(config)
       @mobilized_cop_classes ||= begin
         cop_classes = Cop::Cop.all
 
@@ -71,7 +71,7 @@ def mobilized_cop_classes
           cop_classes.select! { |c| c.cop_name == @options[:only] }
         else
           # filter out Rails cops unless requested
-          cop_classes.reject!(&:rails?) unless @options[:rails]
+          cop_classes.reject!(&:rails?) unless run_rails_cops?(config)
 
           # filter out style cops when --lint is passed
           cop_classes.select!(&:lint?) if @options[:lint]
@@ -83,7 +83,7 @@ def mobilized_cop_classes
 
     def inspect_file(file)
       config = @config_store.for(file)
-      team = Cop::Team.new(mobilized_cop_classes, config, @options)
+      team = Cop::Team.new(mobilized_cop_classes(config), config, @options)
       offences = team.inspect_file(file)
       @errors.concat(team.errors)
       offences
@@ -262,6 +262,10 @@ def display_error_summary(errors)
 
     private
 
+    def run_rails_cops?(config)
+      @options[:rails] || config['AllCops']['RunRailsCops']
+    end
+
     def target_finder
       @target_finder ||= TargetFinder.new(@config_store, @options[:debug])
     end
diff --git a/spec/rubocop/cli_spec.rb b/spec/rubocop/cli_spec.rb
index 908eafb433f0..9d24fc915fb8 100644
--- a/spec/rubocop/cli_spec.rb
+++ b/spec/rubocop/cli_spec.rb
@@ -775,6 +775,43 @@ def interrupt
         .to eq(['', '1 file inspected, no offences detected', ''].join("\n"))
     end
 
+    describe 'enabling/disabling rails cops' do
+      it 'by default does not run rails cops' do
+        create_file('example1.rb', ['# encoding: utf-8',
+                                    'read_attribute(:test)'])
+        expect(cli.run(['--format', 'simple', 'example1.rb'])).to eq(0)
+      end
+
+      it 'with -R given runs rails cops' do
+        create_file('example1.rb', ['# encoding: utf-8',
+                                    'read_attribute(:test)'])
+        expect(cli.run(['--format', 'simple', '-R', 'example1.rb'])).to eq(1)
+        expect($stdout.string).to include('Prefer self[:attribute]')
+      end
+
+      it 'with configation option true runs rails cops' do
+        create_file('example1.rb', ['# encoding: utf-8',
+                                    'read_attribute(:test)'])
+        create_file('.rubocop.yml', [
+                                     'AllCops:',
+                                     '  RunRailsCops: true',
+                                    ])
+        expect(cli.run(['--format', 'simple', 'example1.rb'])).to eq(1)
+        expect($stdout.string).to include('Prefer self[:attribute]')
+      end
+
+      it 'with configation option false but -R given runs rails cops' do
+        create_file('example1.rb', ['# encoding: utf-8',
+                                    'read_attribute(:test)'])
+        create_file('.rubocop.yml', [
+                                     'AllCops:',
+                                     '  RunRailsCops: false',
+                                    ])
+        expect(cli.run(['--format', 'simple', '-R', 'example1.rb'])).to eq(1)
+        expect($stdout.string).to include('Prefer self[:attribute]')
+      end
+    end
+
     describe 'configuration from file' do
       it 'finds included files' do
         create_file('example', [