diff --git a/lib/cucumber/formatter/event_stream.rb b/lib/cucumber/formatter/event_stream.rb
index 6c2d1ae33d..0cdc8a4f7a 100644
--- a/lib/cucumber/formatter/event_stream.rb
+++ b/lib/cucumber/formatter/event_stream.rb
@@ -1,3 +1,6 @@
+require 'securerandom'
+require 'date'
+
 module Cucumber
   module Formatter
     class EventStream
@@ -5,6 +8,7 @@ class EventStream
 
       def initialize(config)
         @config = config
+        @series_id = SecureRandom.uuid
         set_up_event_handlers
       end
 
@@ -18,134 +22,33 @@ def emit(event_data)
         @config.out_stream.puts(event_data.to_json)
       end
 
+      def ms_since_epoch
+        Integer(DateTime.now.strftime('%Q'))
+      end
+
       def set_up_event_handlers
         on(:test_run_started) do
          emit({
-            event: "TestRunStarted",
-            protocol_version: PROTOCOL_VERSION
+            type: "start",
+            timestamp: ms_since_epoch,
+            series: @series_id
           })
         end
 
         on(:gherkin_source_read) do |event|
           emit({
-            event: "GherkinSourceRead",
-            id: "#{event.path}:1",
-            source: event.source
-          })
-        end
-
-        on(:step_match) do
-          emit({
-            event: "StepDefinitionMatched",
-          })
-        end
-
-        on(:test_case_starting) do |event|
-          emit({
-            event: "TestCaseStarted",
-            id: event.test_case.location
-          })
-        end
-
-        on(:test_step_starting) do |event|
-          emit({
-            event: "TestStepStarted",
-            id: event.test_step.location
-          })
-        end
-
-        on(:test_step_finished) do |test_step, result|
-          event_builder = TestStepResultEvent.new(@config)
-          result.describe_to event_builder, test_step
-          emit(event_builder)
-        end
-
-        on(:test_case_finished) do |test_case, result|
-          event_builder = TestCaseResultEvent.new(@config)
-          result.describe_to event_builder, test_case
-          emit(event_builder)
-        end
-
-        on(:test_run_finished) do
-          emit({
-            event: "TestRunFinished"
+            type: "source",
+            timestamp: ms_since_epoch,
+            series: @series_id,
+            uri: event.path, # TODO: should be uri
+            data: event.source,
+            media: {
+              encoding: "utf-8",
+              type: "text/vnd.cucumber.gherkin+plain"
+            }
           })
         end
       end
-
-      class TestStepResultEvent
-        def initialize(config)
-          @config = config
-          @data = {}
-        end
-
-        def passed(test_step)
-          data[:event] = "TestStepPassed"
-          data[:id] = test_step.location
-        end
-
-        def failed(test_step)
-          data[:event] = "TestStepPassed"
-          data[:id] = test_step.location
-        end
-
-        def duration(duration, test_step)
-          data[:duration] = duration.nanoseconds
-        end
-
-        def exception(exception, test_case)
-          data[:error_summary] = exception.message
-          data[:error_detail] = exception.backtrace
-        end
-
-        def to_json
-          data.to_json
-        end
-
-        private
-
-        attr_reader :data
-        private :data
-
-        def emit(event_data)
-          @config.out_stream.puts(event_data.to_json)
-        end
-      end
-
-      class TestCaseResultEvent
-        def initialize(config)
-          @config = config
-          @data = {}
-        end
-
-        def passed(test_step)
-          data[:event] = "TestCasePassed"
-          data[:id] = test_step.location
-        end
-
-        def failed(test_step)
-          data[:event] = "TestCasePassed"
-          data[:id] = test_step.location
-        end
-
-        def duration(duration, test_step)
-          data[:duration] = duration.nanoseconds
-        end
-
-        def to_json
-          data.to_json
-        end
-
-        private
-
-        attr_reader :data
-        private :data
-
-        def emit(event_data)
-          @config.out_stream.puts(event_data.to_json)
-        end
-      end
-
     end
   end
 end