diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 43f76c7..916597e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -12,7 +12,6 @@ jobs:
     runs-on: ubuntu-latest
     continue-on-error: ${{ matrix.experimental }}
     strategy:
-      fail-fast: true
       matrix:
         ruby: [2.3, 2.4, 2.5, 2.6, 2.7, 3.0, jruby, truffleruby]
         mongoid: [7]
@@ -27,9 +26,9 @@ jobs:
           - ruby: 2.3
             mongoid: 3
             experimental: false
-          - ruby: 2.3
-            mongoid: 4
-            experimental: false
+          # - ruby: 2.3
+          #   mongoid: 4
+          #   experimental: false
           - ruby: 2.3
             mongoid: 5
             experimental: false
@@ -64,11 +63,15 @@ jobs:
 
       - name: bundle install
         run:  bundle install --jobs 4 --retry 3
+        env:
+          MONGOID_VERSION: ${{ matrix.mongoid }}
 
       - name: rubocop
         timeout-minutes: 5
         run: bundle exec rubocop
         continue-on-error: ${{ matrix.experimental }}
+        env:
+          MONGOID_VERSION: ${{ matrix.mongoid }}
 
       - name: test
         timeout-minutes: 10
diff --git a/Gemfile b/Gemfile
index 5380df4..82bb5ed 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,5 +21,5 @@ end
 
 group :test do
   gem 'mongoid-danger', '~> 0.1.0', require: false
-  gem 'rubocop', '0.58.2'
+  gem 'rubocop', '0.57.2'
 end
diff --git a/spec/mongoid/slug_spec.rb b/spec/mongoid/slug_spec.rb
index dde8197..c4e401e 100644
--- a/spec/mongoid/slug_spec.rb
+++ b/spec/mongoid/slug_spec.rb
@@ -1134,18 +1134,23 @@ class Person
       before do
         Author.create_indexes
       end
+
       after do
         Author.remove_indexes
       end
+
       it 'can be assigned to nil' do
         expect(Book.slug_max_length).to be nil
       end
+
       it 'defaults to MONGO_INDEX_KEY_LIMIT_BYTES - 32' do
         expect(Article.slug_max_length).to eq Mongoid::Slug::MONGO_INDEX_KEY_LIMIT_BYTES - 32
       end
+
       it 'is assigned via max_length' do
         expect(Author.slug_max_length).to eq 256
       end
+
       it 'enforces max length of slug' do
         author1 = Author.create!(last_name: 't' * 1024)
         expect(author1.slug.length).to eq 256