diff --git a/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb b/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
index 9f85dc49f..3059c23c9 100644
--- a/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
+++ b/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
@@ -43,8 +43,13 @@ module Redmine
         end
 
         def attachments_visible?(user=User.current)
-          (respond_to?(:visible?) ? visible?(user) : true) &&
-            user.allowed_to?(self.class.attachable_options[:view_permission], self.project)
+          if self.respond_to?(:project)
+            (respond_to?(:visible?) ? visible?(user) : true) &&
+                user.allowed_to?(self.class.attachable_options[:view_permission], self.project)
+          else
+            return true
+          end
+
         end
 
         def attachments_deletable?(user=User.current)