diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 539afb2..cf0ec91 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,13 +1,20 @@
-name: build
+name: test
 
 on: [push, pull_request]
 
 jobs:
-  build:
+  ruby-versions:
+    uses: ruby/actions/.github/workflows/ruby_versions.yml@master
+    with:
+      engine: cruby
+      min_version: 2.6
+
+  test:
+    needs: ruby-versions
     name: build (${{ matrix.ruby }} / ${{ matrix.os }})
     strategy:
       matrix:
-        ruby: [ head, '3.0', '2.7', '2.6' ]
+        ruby: ${{ fromJson(needs.ruby-versions.outputs.versions) }}
         os: [ ubuntu-latest, macos-latest, windows-latest ]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/test/ruby/test_random_formatter.rb b/test/ruby/test_random_formatter.rb
index a061946..7c3003e 100644
--- a/test/ruby/test_random_formatter.rb
+++ b/test/ruby/test_random_formatter.rb
@@ -75,7 +75,7 @@ def test_uuid
       assert_match(/\A\h{8}-\h{4}-\h{4}-\h{4}-\h{12}\z/, uuid)
     end
 
-    def test_uuid_v7(extra_timestamp_bits)
+    def test_uuid_v7
       t1 = current_uuid7_time
       uuid = @it.uuid_v7
       t3 = current_uuid7_time