diff --git a/app/models/dependency.rb b/app/models/dependency.rb
new file mode 100644
index 00000000..53c73f65
--- /dev/null
+++ b/app/models/dependency.rb
@@ -0,0 +1,9 @@
+class Dependency < ActiveRecord::Base
+
+  belongs_to :todo, 
+    :class_name => "Todo", :foreign_key => "todo_id"
+  belongs_to :predecessor, 
+    :class_name => "Todo", :foreign_key => "predecessor_id"
+  
+end
+