diff --git a/lib/join_project/patches/project_patch.rb b/lib/join_project/patches/project_patch.rb
index 200f248..209ab8e 100644
--- a/lib/join_project/patches/project_patch.rb
+++ b/lib/join_project/patches/project_patch.rb
@@ -6,6 +6,7 @@ def self.included(base)
         base.extend(ClassMethods)
         base.class_eval do
           validates_inclusion_of :project_subscription, :in => join_options, :allow_nil => true, :allow_blank => 'true'
+          safe_attributes :project_subscription
         end
       end