diff --git a/logstash-core/lib/logstash/event.rb b/logstash-core/lib/logstash/event.rb
index 4be181587..577ece5fb 100644
--- a/logstash-core/lib/logstash/event.rb
+++ b/logstash-core/lib/logstash/event.rb
@@ -1,12 +1,6 @@
 # encoding: utf-8
 
-require "logstash/json"
-
-# transient pipeline events for normal in-flow signaling as opposed to
-# flow altering exceptions. for now having base classes is adequate and
-# in the future it might be necessary to refactor using like a BaseEvent
-# class to have a common interface for all pipeline events to support
-# eventual queueing persistence for example, TBD.
+# used only in the Ruby execution engine
 module LogStash
   class SignalEvent
     def flush?; raise "abstract method"; end;
diff --git a/logstash-core/lib/logstash/java_pipeline.rb b/logstash-core/lib/logstash/java_pipeline.rb
index 896af5e42..18274cc34 100644
--- a/logstash-core/lib/logstash/java_pipeline.rb
+++ b/logstash-core/lib/logstash/java_pipeline.rb
@@ -1,7 +1,6 @@
 # encoding: utf-8
 require "thread"
 require "concurrent"
-require "logstash/event"
 require "logstash/filters/base"
 require "logstash/inputs/base"
 require "logstash/outputs/base"