diff --git a/.gitignore b/.gitignore
index e5791c8..4f15859 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,4 +4,4 @@ Gemfile.lock
 pkg/*
 spec/log
 spec/tmp
-gemfiles/*.lock
+scenarios/*.lock
diff --git a/Appraisals b/Appraisals
deleted file mode 100644
index a2e1454..0000000
--- a/Appraisals
+++ /dev/null
@@ -1,40 +0,0 @@
-appraise "rails30" do
-  gem "rails", "3.0.20"
-  gem "sqlite3"
-end
-
-appraise "rails31" do
-  gem "rails", "3.1.12"
-  gem "mongoid"
-  gem "sqlite3"
-end
-
-appraise "rails32" do
-  gem "rails", "3.2.21"
-  gem "mongoid"
-  gem "sqlite3"
-end
-
-appraise "rails40" do
-  gem "rails", "4.0.13"
-  gem "mongoid"
-  gem "sqlite3"
-end
-
-appraise "rails41" do
-  gem "rails", "4.1.9"
-  gem "mongoid"
-  gem "sqlite3"
-end
-
-appraise "rails42" do
-  gem "rails", "4.2.0"
-  gem "mongoid"
-  gem "sqlite3"
-end
-
-appraise "rails50" do
-  gem "rails", github: "rails/rails"
-  gem 'arel', github: "rails/arel"
-  gem "sqlite3"
-end
diff --git a/Readme.md b/Readme.md
index efa78d6..76334ba 100644
--- a/Readme.md
+++ b/Readme.md
@@ -88,15 +88,27 @@ end
 
 # Developing and Testing
 
-To generate Gemfiles for Rails 3.0, 3.1, 3.2, 4.0, 4.1, and 4.2, run `rake
-appraisal:gemfiles appraisal:install`.
+This repo uses [Roadshow] to generate a [Docker Compose] file for each
+supported version of Rails (with a compatible version of Ruby for each one).
 
-You can then run the tests across all four versions with `rake appraisal`.  You
-can also manually run the Rails console and server with `rake appraisal
-console` and `rake appraisal server`.
+To run specs across all versions, you can either [get the Roadshow tool] and
+run `roadshow run`, or use Docker Compose directly:
 
-For a specific version of Rails, use `rake appraisal:rails30`, `rake
-appraisal:rails31`, `rake appraisal:rails32`, etc.
+```
+$ for fn in scenarios/*.docker-compose-yml; do docker-compose -f $fn run --rm scenario; done
+```
+
+You can also manually run the Rails console and server on each version with
+`roadshow run rake console` and `roadshow run rake server`, or run them on a
+specific version with, e.g., `roadshow run -s rails40 rake console`.
+
+To update the set of scenarios, edit `scenarios.yml` and run `roadshow
+generate`, although the Gemfiles in the `scenarios` directory need to be
+maintained manually.
+
+[Roadshow]: https://github.com/rf-/roadshow
+[Docker Compose]: https://docs.docker.com/compose/
+[get the Roadshow tool]: https://github.com/rf-/roadshow/releases
 
 # Alternative
 
diff --git a/gemfiles/rails40.gemfile b/gemfiles/rails40.gemfile
deleted file mode 100644
index 981498d..0000000
--- a/gemfiles/rails40.gemfile
+++ /dev/null
@@ -1,9 +0,0 @@
-# This file was generated by Appraisal
-
-source "http://rubygems.org"
-
-gem "rails", "4.0.13"
-gem "mongoid"
-gem "sqlite3"
-
-gemspec :path => "../"
diff --git a/gemfiles/rails50.gemfile b/gemfiles/rails50.gemfile
deleted file mode 100644
index 4151a64..0000000
--- a/gemfiles/rails50.gemfile
+++ /dev/null
@@ -1,9 +0,0 @@
-# This file was generated by Appraisal
-
-source "http://rubygems.org"
-
-gem "rails", :github => "rails/rails"
-gem "arel", :github => "rails/arel"
-gem "sqlite3"
-
-gemspec :path => "../"
diff --git a/scenarios.yml b/scenarios.yml
new file mode 100644
index 0000000..26eed81
--- /dev/null
+++ b/scenarios.yml
@@ -0,0 +1,27 @@
+project: pryrails
+
+shared:
+  from: ruby:2.4
+  cmd: "(bundle check || bundle install) && bundle exec rake"
+  service:
+    volumes:
+      - bundle_{{scenario_name}}:/usr/local/bundle
+    environment:
+      BUNDLE_GEMFILE: scenarios/{{scenario_name}}.gemfile
+  volumes:
+    bundle_{{scenario_name}}:
+
+scenarios:
+  rails30:
+    from: ruby:2.0
+  rails31:
+    from: ruby:2.0
+  rails32:
+    from: ruby:2.0
+  rails40:
+    from: ruby:2.3
+  rails41:
+    from: ruby:2.3
+  rails42: {}
+  rails50: {}
+  rails51: {}
diff --git a/scenarios/rails30.docker-compose.yml b/scenarios/rails30.docker-compose.yml
new file mode 100644
index 0000000..78d8fef
--- /dev/null
+++ b/scenarios/rails30.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails30.dockerfile
+    image: pryrails_scenario_rails30
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails30:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails30.gemfile
+volumes:
+  bundle_rails30: {}
diff --git a/scenarios/rails30.dockerfile b/scenarios/rails30.dockerfile
new file mode 100644
index 0000000..cd39487
--- /dev/null
+++ b/scenarios/rails30.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.0
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/gemfiles/rails30.gemfile b/scenarios/rails30.gemfile
similarity index 52%
rename from gemfiles/rails30.gemfile
rename to scenarios/rails30.gemfile
index 2c8f4b3..7444abb 100644
--- a/gemfiles/rails30.gemfile
+++ b/scenarios/rails30.gemfile
@@ -1,8 +1,7 @@
-# This file was generated by Appraisal
-
 source "http://rubygems.org"
 
-gem "rails", "3.0.20"
+gem "rails", "~> 3.0.0"
 gem "sqlite3"
+gem "test-unit"
 
 gemspec :path => "../"
diff --git a/scenarios/rails31.docker-compose.yml b/scenarios/rails31.docker-compose.yml
new file mode 100644
index 0000000..8382cab
--- /dev/null
+++ b/scenarios/rails31.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails31.dockerfile
+    image: pryrails_scenario_rails31
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails31:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails31.gemfile
+volumes:
+  bundle_rails31: {}
diff --git a/scenarios/rails31.dockerfile b/scenarios/rails31.dockerfile
new file mode 100644
index 0000000..cd39487
--- /dev/null
+++ b/scenarios/rails31.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.0
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/gemfiles/rails31.gemfile b/scenarios/rails31.gemfile
similarity index 56%
rename from gemfiles/rails31.gemfile
rename to scenarios/rails31.gemfile
index 970782f..43c7820 100644
--- a/gemfiles/rails31.gemfile
+++ b/scenarios/rails31.gemfile
@@ -1,9 +1,8 @@
-# This file was generated by Appraisal
-
 source "http://rubygems.org"
 
-gem "rails", "3.1.12"
+gem "rails", "~> 3.1.0"
 gem "mongoid"
 gem "sqlite3"
+gem "test-unit"
 
 gemspec :path => "../"
diff --git a/scenarios/rails32.docker-compose.yml b/scenarios/rails32.docker-compose.yml
new file mode 100644
index 0000000..2fc141b
--- /dev/null
+++ b/scenarios/rails32.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails32.dockerfile
+    image: pryrails_scenario_rails32
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails32:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails32.gemfile
+volumes:
+  bundle_rails32: {}
diff --git a/scenarios/rails32.dockerfile b/scenarios/rails32.dockerfile
new file mode 100644
index 0000000..cd39487
--- /dev/null
+++ b/scenarios/rails32.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.0
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/gemfiles/rails32.gemfile b/scenarios/rails32.gemfile
similarity index 56%
rename from gemfiles/rails32.gemfile
rename to scenarios/rails32.gemfile
index 4f009db..5488d16 100644
--- a/gemfiles/rails32.gemfile
+++ b/scenarios/rails32.gemfile
@@ -1,9 +1,8 @@
-# This file was generated by Appraisal
-
 source "http://rubygems.org"
 
-gem "rails", "3.2.21"
+gem "rails", "~> 3.2.0"
 gem "mongoid"
 gem "sqlite3"
+gem "test-unit"
 
 gemspec :path => "../"
diff --git a/scenarios/rails40.docker-compose.yml b/scenarios/rails40.docker-compose.yml
new file mode 100644
index 0000000..9ffd3e3
--- /dev/null
+++ b/scenarios/rails40.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails40.dockerfile
+    image: pryrails_scenario_rails40
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails40:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails40.gemfile
+volumes:
+  bundle_rails40: {}
diff --git a/scenarios/rails40.dockerfile b/scenarios/rails40.dockerfile
new file mode 100644
index 0000000..7e898d0
--- /dev/null
+++ b/scenarios/rails40.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.3
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/scenarios/rails40.gemfile b/scenarios/rails40.gemfile
new file mode 100644
index 0000000..2f4b477
--- /dev/null
+++ b/scenarios/rails40.gemfile
@@ -0,0 +1,6 @@
+source "http://rubygems.org"
+
+gem "rails", "~> 4.0.0"
+gem "sqlite3"
+
+gemspec :path => "../"
diff --git a/scenarios/rails41.docker-compose.yml b/scenarios/rails41.docker-compose.yml
new file mode 100644
index 0000000..a7d3232
--- /dev/null
+++ b/scenarios/rails41.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails41.dockerfile
+    image: pryrails_scenario_rails41
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails41:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails41.gemfile
+volumes:
+  bundle_rails41: {}
diff --git a/scenarios/rails41.dockerfile b/scenarios/rails41.dockerfile
new file mode 100644
index 0000000..7e898d0
--- /dev/null
+++ b/scenarios/rails41.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.3
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/gemfiles/rails41.gemfile b/scenarios/rails41.gemfile
similarity index 57%
rename from gemfiles/rails41.gemfile
rename to scenarios/rails41.gemfile
index d6ea7ff..001966c 100644
--- a/gemfiles/rails41.gemfile
+++ b/scenarios/rails41.gemfile
@@ -1,8 +1,6 @@
-# This file was generated by Appraisal
-
 source "http://rubygems.org"
 
-gem "rails", "4.1.9"
+gem "rails", "~> 4.1.0"
 gem "mongoid"
 gem "sqlite3"
 
diff --git a/scenarios/rails42.docker-compose.yml b/scenarios/rails42.docker-compose.yml
new file mode 100644
index 0000000..e7bb7ba
--- /dev/null
+++ b/scenarios/rails42.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails42.dockerfile
+    image: pryrails_scenario_rails42
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails42:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails42.gemfile
+volumes:
+  bundle_rails42: {}
diff --git a/scenarios/rails42.dockerfile b/scenarios/rails42.dockerfile
new file mode 100644
index 0000000..8f8ed2c
--- /dev/null
+++ b/scenarios/rails42.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.4
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/gemfiles/rails42.gemfile b/scenarios/rails42.gemfile
similarity index 57%
rename from gemfiles/rails42.gemfile
rename to scenarios/rails42.gemfile
index d0d8a96..a66961e 100644
--- a/gemfiles/rails42.gemfile
+++ b/scenarios/rails42.gemfile
@@ -1,8 +1,6 @@
-# This file was generated by Appraisal
-
 source "http://rubygems.org"
 
-gem "rails", "4.2.0"
+gem "rails", "~> 4.2.0"
 gem "mongoid"
 gem "sqlite3"
 
diff --git a/scenarios/rails50.docker-compose.yml b/scenarios/rails50.docker-compose.yml
new file mode 100644
index 0000000..b9d3609
--- /dev/null
+++ b/scenarios/rails50.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails50.dockerfile
+    image: pryrails_scenario_rails50
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails50:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails50.gemfile
+volumes:
+  bundle_rails50: {}
diff --git a/scenarios/rails50.dockerfile b/scenarios/rails50.dockerfile
new file mode 100644
index 0000000..8f8ed2c
--- /dev/null
+++ b/scenarios/rails50.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.4
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/scenarios/rails50.gemfile b/scenarios/rails50.gemfile
new file mode 100644
index 0000000..79a5069
--- /dev/null
+++ b/scenarios/rails50.gemfile
@@ -0,0 +1,7 @@
+source "http://rubygems.org"
+
+gem "rails", "~> 5.0.0"
+gem "mongoid"
+gem "sqlite3"
+
+gemspec :path => "../"
diff --git a/scenarios/rails51.docker-compose.yml b/scenarios/rails51.docker-compose.yml
new file mode 100644
index 0000000..73e2e43
--- /dev/null
+++ b/scenarios/rails51.docker-compose.yml
@@ -0,0 +1,15 @@
+---
+version: "2"
+services:
+  scenario:
+    build:
+      context: ..
+      dockerfile: scenarios/rails51.dockerfile
+    image: pryrails_scenario_rails51
+    volumes:
+    - "..:/scenario"
+    - "bundle_rails51:/usr/local/bundle"
+    environment:
+      BUNDLE_GEMFILE: scenarios/rails51.gemfile
+volumes:
+  bundle_rails51: {}
diff --git a/scenarios/rails51.dockerfile b/scenarios/rails51.dockerfile
new file mode 100644
index 0000000..8f8ed2c
--- /dev/null
+++ b/scenarios/rails51.dockerfile
@@ -0,0 +1,5 @@
+FROM ruby:2.4
+RUN mkdir -p /scenario
+WORKDIR /scenario
+ENV LANG=C.UTF-8
+CMD (bundle check || bundle install) && bundle exec rake
diff --git a/scenarios/rails51.gemfile b/scenarios/rails51.gemfile
new file mode 100644
index 0000000..e67d1dc
--- /dev/null
+++ b/scenarios/rails51.gemfile
@@ -0,0 +1,7 @@
+source "http://rubygems.org"
+
+gem "rails", "~> 5.1.0"
+gem "mongoid"
+gem "sqlite3"
+
+gemspec :path => "../"