1 files changed, 6 insertions, 2 deletions
diff --git a/activemodel/lib/active_model/state_machine/machine.rb b/activemodel/lib/active_model/state_machine/machine.rb
index 170505c0b2..a5ede021b1 100644
--- a/activemodel/lib/active_model/state_machine/machine.rb
+++ b/activemodel/lib/active_model/state_machine/machine.rb
@@ -1,7 +1,11 @@
+require 'active_model/state_machine/state'
+require 'active_model/state_machine/event'
+
 module ActiveModel
   module StateMachine
     class Machine
-      attr_accessor :initial_state, :states, :events, :state_index
+      attr_writer :initial_state
+      attr_accessor :states, :events, :state_index
       attr_reader :klass, :name
 
       def initialize(klass, name, options = {}, &block)
@@ -71,4 +75,4 @@ module ActiveModel
       end
     end
   end
-end
-\ No newline at end of file
+end