diff --git a/lib/rubocop/extension/generator/generator.rb b/lib/rubocop/extension/generator/generator.rb
index 667ed3e..02d90e5 100644
--- a/lib/rubocop/extension/generator/generator.rb
+++ b/lib/rubocop/extension/generator/generator.rb
@@ -98,6 +98,7 @@ def self.defaults!
           patch "lib/#{dirname}.rb", 'module Rubocop', 'module RuboCop'
           patch "lib/#{dirname}/version.rb", 'module Rubocop', 'module RuboCop'
           patch "#{name}.gemspec", 'Rubocop', 'RuboCop'
+          patch "spec/#{dirname}_spec.rb", 'Rubocop::', 'RuboCop::'
 
           patch "#{name}.gemspec", /^end/, <<~RUBY
 
@@ -105,13 +106,9 @@ def self.defaults!
             end
           RUBY
 
-          patch "Rakefile", /\z/, <<~RUBY
-
-            require 'rspec/core/rake_task'
+          patch_rakefile
 
-            RSpec::Core::RakeTask.new(:spec) do |spec|
-              spec.pattern = FileList['spec/**/*_spec.rb']
-            end
+          patch "Rakefile", /\z/, <<~RUBY
 
             desc 'Generate a new cop with a template'
             task :new_cop, [:cop] do |_task, args|
@@ -136,9 +133,7 @@ def self.defaults!
             end
           RUBY
 
-          patch 'Gemfile', /\z/, <<~RUBY
-            gem 'rspec'
-          RUBY
+          patch_gemfile
 
           patch 'README.md', /^gem '#{name}'$/, "gem '#{name}', require: false"
 
@@ -151,6 +146,32 @@ def self.defaults!
           MESSAGE
         end
 
+        private def has_rspec?
+          path = root_path / 'Gemfile'
+          file = path.read
+          return true if file =~ (/gem ('|")rspec('|")/)
+        end
+
+        private def patch_gemfile
+          return if has_rspec?
+          patch 'Gemfile', /\z/, <<~RUBY
+            gem 'rspec'
+          RUBY
+        end
+
+        private def patch_rakefile
+          return if has_rspec?
+          patch 'Rakefile', /\z/, <<~RUBY
+
+            require 'rspec/core/rake_task'
+
+            RSpec::Core::RakeTask.new(:spec) do |spec|
+              spec.pattern = FileList['spec/**/*_spec.rb']
+            end
+          RUBY
+
+        end
+
         private def put(path, content)
           path = root_path / path
           puts "create #{path}"
@@ -163,7 +184,7 @@ def self.defaults!
           path = root_path / path
           file = path.read
           raise "Cannot apply patch for #{path} because #{pattern} is missing" unless file.match?(pattern)
-          path.write file.sub(pattern, replacement)
+          path.write file.gsub(pattern, replacement)
         end
 
         private def root_path
diff --git a/smoke/smoke.rb b/smoke/smoke.rb
index 15707af..1ff891f 100644
--- a/smoke/smoke.rb
+++ b/smoke/smoke.rb
@@ -9,6 +9,7 @@
 Dir.mktmpdir('-rubocop-extension-generator-smoke') do |base_dir|
   base_dir = Pathname(base_dir)
   gem_name = 'rubocop-smoke'
+  gem_namespace = gem_name.sub('-', '/')
   gem_dir = base_dir / gem_name
 
   system({ 'RUBYLIB' => load_path }, 'ruby', exe_path, gem_name, exception: true, chdir: base_dir)
@@ -22,6 +23,12 @@
 
   gemspec_path.write gemspec
 
+  spec = gem_dir / "spec/#{gem_namespace}_spec.rb"
+  specfile = spec.read
+  specfile.gsub!('expect(false).to eq(true)', 'expect(true).to eq(true)')
+
+  spec.write specfile
+
   system('bundle', 'install', exception: true, chdir: gem_dir)
   system('bundle', 'exec', 'rake', 'new_cop[Smoke/Foo]', exception: true, chdir: gem_dir)
   system('bundle', 'exec', 'rake', 'spec', exception: true, chdir: gem_dir)