diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 6bdfe5e..fe80aed 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -53,22 +53,8 @@ jobs:
           bundle
           bundle exec rake
       - name: Set up new Rails dummy app
-        working-directory: ./spec
-        env:
-          RAILS_NEW_GEMFILE: dummy_app_config/gemfiles/Gemfile-rails-${{ matrix.rails-version }}
         run: |
-          bundle config set --local path '/tmp/system-tests'
-          BUNDLE_GEMFILE=$RAILS_NEW_GEMFILE bundle
-          rails new dummy_app --database=sqlite3 --skip-active-storage --skip-action-cable --skip-spring --skip-listen --skip-test
-          cat dummy_app_config/Gemfile.append >> dummy_app/Gemfile
-          cd dummy_app
-          bundle
-          rails g rspec:install
-          cp -rf ../dummy_app_config/shared_source/all/* ./
-          cp -rf ../dummy_app_config/shared_source/${{ matrix.rails-version }}/* ./
-          yarn install
+          bin/set-up-dummy-app ${{ matrix.rails-version }}
       - name: Run Rails dummy app tests
-        working-directory: ./spec/dummy_app
         run: |
-          rake db:drop db:create db:migrate
-          rake
+          bundle exec rails db:drop db:create db:migrate spec
diff --git a/README.md b/README.md
index 5f335d5..ceb2146 100644
--- a/README.md
+++ b/README.md
@@ -590,6 +590,16 @@ Other Ruby libraries that offer passwordless authentication:
 * [passwordless](https://github.com/mikker/passwordless)
 * [magic-link](https://github.com/dvanderbeek/magic-link)
 
+## Gem development
+
+### Running tests
+
+```
+bin/dummy-app-setup 6.1
+cd spec/tmp/dummy_app-rails-6.1/dummy_app
+bundle exec rails db:drop db:create db:migrate spec
+```
+
 ## License
 
 The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).
diff --git a/bin/dummy-app-setup b/bin/dummy-app-setup
new file mode 100755
index 0000000..da49701
--- /dev/null
+++ b/bin/dummy-app-setup
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+set -xeuo pipefail
+
+DIRECTORY=spec/tmp/dummy_app-rails-$1
+
+mkdir -p $DIRECTORY
+cp spec/dummy_app_config/gemfiles/Gemfile-rails-$1 $DIRECTORY/Gemfile
+cd $DIRECTORY
+bundle config set --local path gems
+bundle install
+bundle exec rails new dummy_app --database=sqlite3 --skip-active-storage --skip-action-cable --skip-spring --skip-listen --skip-test --skip-bootsnap
+cat ../../dummy_app_config/Gemfile.append >> dummy_app/Gemfile
+cd dummy_app
+bundle install
+bundle exec rails generate rspec:install
+cp -rf ../../../dummy_app_config/shared_source/all/* ./
+cp -rf ../../../dummy_app_config/shared_source/$1/* ./
+yarn install
diff --git a/spec/dummy_app_config/Gemfile.append b/spec/dummy_app_config/Gemfile.append
index 02a55d8..de46b52 100644
--- a/spec/dummy_app_config/Gemfile.append
+++ b/spec/dummy_app_config/Gemfile.append
@@ -7,4 +7,4 @@ group :development, :test do
 end
 
 gem "devise"
-gem "devise-passwordless", :path => "../../../"
+gem "devise-passwordless", :path => "../../../../"