diff --git a/lib/statesman/adapters/active_record.rb b/lib/statesman/adapters/active_record.rb
index c98eadfb..6e848267 100644
--- a/lib/statesman/adapters/active_record.rb
+++ b/lib/statesman/adapters/active_record.rb
@@ -197,8 +197,8 @@ def with_updated_timestamp(params)
     end
 
     class ActiveRecordAfterCommitWrap
-      def initialize
-        @callback = Proc.new
+      def initialize(&block)
+        @callback = block
         @connection = ::ActiveRecord::Base.connection
       end