diff --git a/app/models/project.rb b/app/models/project.rb
index 671542b..c7dfc90 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -13,7 +13,7 @@ class Project
   field :participator, localize: true
   field :unit, localize: true
   
-  field :year
+  field :year, type: Integer
   field :language
   field :keywords
   field :abstract