diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 553edb712..feb88b808 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -19,7 +19,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        ruby: ['3.1', '3.2', '3.3', '3.4']
+        ruby: ['3.2', '3.3', '3.4']
         include:
           - os: ubuntu-latest
             ruby: jruby-9.4
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 4de7e2df5..e363b922d 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -17,7 +17,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        ruby: ['3.1', '3.2', '3.3', '3.4']
+        ruby: ['3.2', '3.3', '3.4']
         include:
           - os: ubuntu-latest
             ruby: jruby-9.4
diff --git a/lib/cucumber/formatter/message_builder.rb b/lib/cucumber/formatter/message_builder.rb
index 7285083e5..dd10d3ce7 100644
--- a/lib/cucumber/formatter/message_builder.rb
+++ b/lib/cucumber/formatter/message_builder.rb
@@ -41,16 +41,13 @@ def initialize(config)
         @current_test_step_id = nil
       end
 
-      def output_message
-        raise 'To be implemented'
-      end
-
       def attach(src, media_type, filename)
         attachment_data = {
           test_step_id: @current_test_step_id,
           test_case_started_id: @current_test_case_started_id,
           media_type: media_type,
-          file_name: filename
+          file_name: filename,
+          timestamp: time_to_timestamp(Time.now)
         }
 
         if media_type&.start_with?('text/')