diff --git a/app/models/issue.rb b/app/models/issue.rb
index b9a2b20a9..2c2e9f087 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -200,7 +200,7 @@ class Issue < ActiveRecord::Base
 
   # Overrides Redmine::Acts::Customizable::InstanceMethods#available_custom_fields
   def available_custom_fields
-    (project && tracker) ? (project.all_issue_custom_fields & tracker.custom_fields.all) : []
+    (project && tracker) ? (project.all_issue_custom_fields & tracker.custom_fields) : []
   end
 
   def visible_custom_field_values(user=nil)