diff --git a/app/helpers/projects_helper.rb b/app/helpers/projects_helper.rb
index a9fb3f881..155d220d9 100644
--- a/app/helpers/projects_helper.rb
+++ b/app/helpers/projects_helper.rb
@@ -52,7 +52,7 @@ module ProjectsHelper
       type: project.numerical_for_project_type,
       author: render_owner(project),
       is_secret: project.is_secret,
-      is_member: !project.members.where(user_id: user.id).blank?,
+      is_member: project.member?(user.id),
       user_apply_signatures: project.apply_signatures.with_user_id(user.id).collect{|s| {id: s.id, status: s.status}}
     }).compact
 
diff --git a/app/views/projects/index.json.jbuilder b/app/views/projects/index.json.jbuilder
index 2c02616de..d66c44a30 100644
--- a/app/views/projects/index.json.jbuilder
+++ b/app/views/projects/index.json.jbuilder
@@ -48,7 +48,7 @@ json.projects @projects do |project|
       json.name project.project_language.name
     end
   end
-  json.is_member !project.members.where(user_id: current_user.id).blank? 
+  json.is_member project.member?(current_user.id)
   user_apply_signatures = project.apply_signatures.with_user_id(current_user.id)
   json.user_apply_signatures user_apply_signatures do |signature|
     json.id signature.id