diff --git a/lib/state_machine/event_collection.rb b/lib/state_machine/event_collection.rb
index 83a40a46..372b7373 100644
--- a/lib/state_machine/event_collection.rb
+++ b/lib/state_machine/event_collection.rb
@@ -1,3 +1,5 @@
+require 'state_machine/node_collection'
+
 module StateMachine
   # Represents a collection of events in a state machine
   class EventCollection < NodeCollection