diff --git a/app/models/external_user.rb b/app/models/external_user.rb
index 24baa284..538f4997 100644
--- a/app/models/external_user.rb
+++ b/app/models/external_user.rb
@@ -6,9 +6,9 @@ class ExternalUser < ActiveRecord::Base
 
   def displayname
     result = name
-    Rails.cache.fetch("#{cache_key}/displayname", expires_in: 12.hours) do
-      if(consumer.name == 'openHPI')
-        result = Xikolo::UserClient.get(external_id.to_s)[:display_name]
+    if(consumer.name == 'openHPI')
+      result = Rails.cache.fetch("#{cache_key}/displayname", expires_in: 12.hours) do
+         Xikolo::UserClient.get(external_id.to_s)[:display_name]
       end
     end
     result