diff --git a/spec/aruba/dbconsole_spec.rb b/spec/aruba/dbconsole_spec.rb
index 8fab834..9ffab3a 100644
--- a/spec/aruba/dbconsole_spec.rb
+++ b/spec/aruba/dbconsole_spec.rb
@@ -3,11 +3,12 @@
 require 'spec_helper'
 
 RSpec.describe 'rails dbconsole', type: :aruba do
+  subject { action && last_command_started }
+
   let(:action) { run_command("bash -c \"echo 'select 1 as foo_column; \\q' | bundle exec rails db\"") }
-  let(:last_command) { action && last_command_started }
 
   before { copy_db_config }
 
-  it { expect(last_command).to be_successfully_executed }
-  it { expect(last_command).to have_output(/\bfoo_column\b/) }
+  it { is_expected.to be_successfully_executed }
+  it { is_expected.to have_output(/\bfoo_column\b/) }
 end
diff --git a/spec/aruba/migrations_spec.rb b/spec/aruba/migrations_spec.rb
index b2e0ce7..0a8014f 100644
--- a/spec/aruba/migrations_spec.rb
+++ b/spec/aruba/migrations_spec.rb
@@ -8,34 +8,37 @@
   context 'when a migration is generated' do
     before { run_command_and_stop('bundle exec rails g migration CreateModels name:string') }
 
-    describe 'bundle exec rake db:migrate' do
-      let(:action) { run_command('bundle exec rake db:migrate') }
-      let(:last_command) { action && last_command_started }
+    describe 'bundle exec rails db:migrate' do
+      subject { action && last_command_started }
 
-      it { expect(last_command).to be_successfully_executed }
-      it { expect(last_command).to have_output(/CreateModels: migrated/) }
+      let(:action) { run_command('bundle exec rails db:migrate') }
+
+      it { is_expected.to be_successfully_executed }
+      it { is_expected.to have_output(/CreateModels: migrated/) }
     end
   end
 
-  describe 'rerun bundle exec rake db:drop db:create db:migrate', issue: 56 do
-    let(:command) { 'bundle exec rake db:drop db:create db:migrate' }
+  describe 'rerun bundle exec rails db:drop db:create db:migrate', issue: 56 do
+    subject { action && last_command_started }
+
+    let(:command) { 'bundle exec rails db:drop db:create db:migrate' }
     let(:action) { run_command(command) }
     let(:regex) { /-- change_table\(:impressions, {:temporal=>true, :copy_data=>true}\)/ }
 
     before { copy('%/migrations/56/', 'db/migrate') }
 
     describe 'once' do
-      let(:last_command) { action && last_command_started }
-
-      it { expect(last_command).to be_successfully_executed }
-      it { expect(last_command).to have_output(regex) }
+      it { is_expected.to be_successfully_executed }
+      it { is_expected.to have_output(regex) }
     end
 
     describe 'twice' do
-      let(:last_command) { run_command_and_stop(command) && action && last_command_started }
+      before do
+        action
+      end
 
-      it { expect(last_command).to be_successfully_executed }
-      it { expect(last_command).to have_output(regex) }
+      it { is_expected.to be_successfully_executed }
+      it { is_expected.to have_output(regex) }
     end
   end
 end
diff --git a/spec/aruba/rake_task_spec.rb b/spec/aruba/rake_task_spec.rb
index cae6f85..54a72b1 100644
--- a/spec/aruba/rake_task_spec.rb
+++ b/spec/aruba/rake_task_spec.rb
@@ -22,21 +22,23 @@
   end
 
   describe dump_schema_task.to_s do
+    subject { last_command_started }
+
     let(:db_file) { 'db/test.sql' }
 
     before do
       copy_db_config
-      run_command_and_stop("bundle exec rake #{dump_schema_task} SCHEMA=db/test.sql")
+      run_command_and_stop("bundle exec rails #{dump_schema_task} SCHEMA=db/test.sql")
     end
 
-    it { expect(last_command_started).to be_successfully_executed }
+    it { is_expected.to be_successfully_executed }
     it { expect(db_file).to be_an_existing_file }
     it { expect(db_file).not_to have_file_content(/\A--/) }
 
     context 'with schema_search_path option' do
       before do
         copy_db_config('database_with_schema_search_path.yml')
-        run_command_and_stop("bundle exec rake #{dump_schema_task} SCHEMA=db/test.sql")
+        run_command_and_stop("bundle exec rails #{dump_schema_task} SCHEMA=db/test.sql")
       end
 
       it 'includes chronomodel schemas' do
@@ -51,15 +53,16 @@
     before do
       copy_db_config
       copy('%/set_config.sql', 'db/test.sql')
-      run_command_and_stop('bundle exec rake db:schema:load SCHEMA=db/test.sql')
+      run_command_and_stop('bundle exec rails db:schema:load SCHEMA=db/test.sql')
     end
 
     it { expect(last_command_started).to be_successfully_executed }
   end
 
   describe load_schema_task.to_s do
-    let(:action) { run_command("bundle exec rake #{load_schema_task}") }
-    let(:last_command) { action && last_command_started }
+    subject { action && last_command_started }
+
+    let(:action) { run_command("bundle exec rails #{load_schema_task}") }
 
     context 'with db/structure.sql' do
       before do
@@ -86,13 +89,13 @@
           end
         end
 
-        it { expect(last_command).to be_successfully_executed }
+        it { is_expected.to be_successfully_executed }
       end
 
       context 'without a specified username and password', issue: 55 do
         before { copy_db_config }
 
-        it { expect(last_command).to be_successfully_executed }
+        it { is_expected.to be_successfully_executed }
       end
     end
   end
@@ -101,7 +104,7 @@
     before do
       copy_db_config
       copy('%/set_config.sql', 'db/test.sql')
-      run_command_and_stop('bundle exec rake db:data:dump DUMP=db/test.sql')
+      run_command_and_stop('bundle exec rails db:data:dump DUMP=db/test.sql')
     end
 
     it { expect(last_command_started).to be_successfully_executed }
@@ -112,7 +115,7 @@
     before do
       copy_db_config
       copy('%/empty_structure.sql', 'db/test.sql')
-      run_command_and_stop('bundle exec rake db:data:load DUMP=db/test.sql')
+      run_command_and_stop('bundle exec rails db:data:load DUMP=db/test.sql')
     end
 
     it { expect(last_command_started).to be_successfully_executed }
diff --git a/spec/aruba/subclasses_spec.rb b/spec/aruba/subclasses_spec.rb
index 5ccaf89..e41f03b 100644
--- a/spec/aruba/subclasses_spec.rb
+++ b/spec/aruba/subclasses_spec.rb
@@ -3,8 +3,9 @@
 require 'spec_helper'
 
 RSpec.describe 'subclasses spec', type: :aruba do
+  subject(:last_command) { action && last_command_started }
+
   let(:action) { run_command('bundle exec rails runner "Foo.subclasses"') }
-  let(:last_command) { action && last_command_started }
 
   before do
     set_environment_variable 'CM_TEST_EAGER_LOAD', true