diff --git a/app/controllers/organizations_controller.rb b/app/controllers/organizations_controller.rb
index f3267447e..53db59afb 100644
--- a/app/controllers/organizations_controller.rb
+++ b/app/controllers/organizations_controller.rb
@@ -50,7 +50,7 @@ curl http://localhost/api/v1/organizations.json -v -u #{login}:#{password}
 
     # only allow customer to fetch his own organization
     organizations = []
-    if is_role('Customer') && !is_role('Admin') && !is_role('Agent')
+    if is_role(Z_ROLENAME_CUSTOMER) && !is_role('Admin') && !is_role('Agent')
       if current_user.organization_id
         organizations = Organization.where( :id => current_user.organization_id )
       end
@@ -80,7 +80,7 @@ curl http://localhost/api/v1/organizations/#{id}.json -v -u #{login}:#{password}
   def show
 
     # only allow customer to fetch his own organization
-    if is_role('Customer') && !is_role('Admin') && !is_role('Agent')
+    if is_role(Z_ROLENAME_CUSTOMER) && !is_role('Admin') && !is_role('Agent')
       if !current_user.organization_id
         render :json => {}
         return
diff --git a/app/controllers/sessions/collection_base.rb b/app/controllers/sessions/collection_base.rb
index 11e8012cd..a282ab3af 100644
--- a/app/controllers/sessions/collection_base.rb
+++ b/app/controllers/sessions/collection_base.rb
@@ -24,7 +24,7 @@ module ExtraCollection
     Group.all.each {|item|
       assets = item.assets(assets)
     }
-    if !user.is_role('Customer')
+    if !user.is_role(Z_ROLENAME_CUSTOMER)
       collections[ Organization.to_app_model ] = []
       Organization.all.each {|item|
         assets = item.assets(assets)
diff --git a/app/controllers/sessions/collection_ticket.rb b/app/controllers/sessions/collection_ticket.rb
index 3b23d3c9f..6a91072bb 100644
--- a/app/controllers/sessions/collection_ticket.rb
+++ b/app/controllers/sessions/collection_ticket.rb
@@ -24,7 +24,7 @@ module ExtraCollection
     Ticket::Article::Sender.all.each {|item|
       assets = item.assets(assets)
     }
-    if !user.is_role('Customer')
+    if !user.is_role(Z_ROLENAME_CUSTOMER)
 
       # all signatures
       collections[ Signature.to_app_model ] = []
diff --git a/app/controllers/tickets_controller.rb b/app/controllers/tickets_controller.rb
index a434f2bf0..c7e7fff1f 100644
--- a/app/controllers/tickets_controller.rb
+++ b/app/controllers/tickets_controller.rb
@@ -241,7 +241,7 @@ class TicketsController < ApplicationController
     articles.each {|article|
 
       # ignore internal article if customer is requesting
-      next if article.internal == true && is_role('Customer')
+      next if article.internal == true && is_role(Z_ROLENAME_CUSTOMER)
 
       # load article ids
       article_ids.push article.id
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 546879a55..b3944ad6a 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -15,7 +15,7 @@ class UsersController < ApplicationController
   def index
 
     # only allow customer to fetch him self
-    if is_role('Customer') && !is_role('Admin') && !is_role('Agent')
+    if is_role(Z_ROLENAME_CUSTOMER) && !is_role('Admin') && !is_role('Agent')
       users = User.where( :id => current_user.id )
     else
       users = User.all
@@ -94,7 +94,7 @@ class UsersController < ApplicationController
 
           # everybody else will go as customer per default
         else
-          role_ids.push Role.where( :name => 'Customer' ).first.id
+          role_ids.push Role.where( :name => Z_ROLENAME_CUSTOMER ).first.id
         end
         user.role_ids  = role_ids
         user.group_ids = group_ids
@@ -260,7 +260,7 @@ class UsersController < ApplicationController
   # @response_message 401               Invalid session.
   def search
 
-    if is_role('Customer') && !is_role('Admin') && !is_role('Agent')
+    if is_role(Z_ROLENAME_CUSTOMER) && !is_role('Admin') && !is_role('Agent')
       response_access_deny
       return
     end
@@ -727,7 +727,7 @@ curl http://localhost/api/v1/users/avatar -v -u #{login}:#{password} -H "Content
     return true if is_role('Agent')
 
     # allow to update customer by him self
-    return true if is_role('Customer') && params[:id].to_i == current_user.id
+    return true if is_role(Z_ROLENAME_CUSTOMER) && params[:id].to_i == current_user.id
 
     response_access_deny
     return false
diff --git a/app/models/user/permission.rb b/app/models/user/permission.rb
index 960cfdb5e..b27dd0458 100644
--- a/app/models/user/permission.rb
+++ b/app/models/user/permission.rb
@@ -18,7 +18,7 @@ returns
   def permission (data)
 
     # check customer
-    if data[:current_user].is_role('Customer')
+    if data[:current_user].is_role(Z_ROLENAME_CUSTOMER)
 
       # access ok if its own user
       return true if self.id == data[:current_user].id