diff --git a/.circleci/config.yml b/.circleci/config.yml
index 970502b..a0d1c3e 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1,9 +1,11 @@
-version: 2
+version: 2.1
 
 jobs:
   ruby_2_6_x86_64:
-    machine:
-      image: ruby:2.6
+    docker:
+      - image: ruby:2.6
+        environment:
+          STEALTH_ENV: test
 
     working_directory: ~/repo
 
@@ -16,11 +18,6 @@ jobs:
             gem install bundler
             bundle install --jobs=4 --retry=3 --path vendor/bundle
 
-      - save_cache:
-          paths:
-            - ./vendor/bundle
-          key: v1-dependencies-{{ checksum "Gemfile.lock" }}
-
       # run tests!
       - run:
           name: run tests
@@ -36,8 +33,8 @@ jobs:
           path: /tmp/test-results
           destination: test-results
   ruby_2_7_x86_64:
-    machine:
-      image: ruby:2.7
+    docker:
+      - image: ruby:2.7
 
     working_directory: ~/repo
 
@@ -50,81 +47,6 @@ jobs:
             gem install bundler
             bundle install --jobs=4 --retry=3 --path vendor/bundle
 
-      - save_cache:
-          paths:
-            - ./vendor/bundle
-          key: v1-dependencies-{{ checksum "Gemfile.lock" }}
-
-      # run tests!
-      - run:
-          name: run tests
-          command: |
-            mkdir /tmp/test-results
-
-            bundle exec rake full
-
-      # collect reports
-      - store_test_results:
-          path: /tmp/test-results
-      - store_artifacts:
-          path: /tmp/test-results
-          destination: test-results
-  ruby_2_6_arm64:
-    resource_class: arm.medium
-    machine:
-      image: ruby:2.6
-
-    working_directory: ~/repo
-
-    steps:
-      - checkout
-
-      - run:
-          name: install dependencies
-          command: |
-            gem install bundler
-            bundle install --jobs=4 --retry=3 --path vendor/bundle
-
-      - save_cache:
-          paths:
-            - ./vendor/bundle
-          key: v1-dependencies-{{ checksum "Gemfile.lock" }}
-
-      # run tests!
-      - run:
-          name: run tests
-          command: |
-            mkdir /tmp/test-results
-
-            bundle exec rake full
-
-      # collect reports
-      - store_test_results:
-          path: /tmp/test-results
-      - store_artifacts:
-          path: /tmp/test-results
-          destination: test-results
-  ruby_2_7_arm64:
-    resource_class: arm.medium
-    machine:
-      image: ruby:2.7
-
-    working_directory: ~/repo
-
-    steps:
-      - checkout
-
-      - run:
-          name: install dependencies
-          command: |
-            gem install bundler
-            bundle install --jobs=4 --retry=3 --path vendor/bundle
-
-      - save_cache:
-          paths:
-            - ./vendor/bundle
-          key: v1-dependencies-{{ checksum "Gemfile.lock" }}
-
       # run tests!
       - run:
           name: run tests
@@ -146,5 +68,3 @@ workflows:
     jobs:
       - ruby_2_6_x86_64
       - ruby_2_7_x86_64
-      - ruby_2_6_arm64
-      - ruby_2_7_arm64