diff -r 92d854be33d5 -r 6106c49c5f50 plugins/redmine_bibliography/app/models/authorship.rb
--- a/plugins/redmine_bibliography/app/models/authorship.rb
+++ b/plugins/redmine_bibliography/app/models/authorship.rb
@@ -128,7 +128,8 @@
         # create new author and update user
         author = Author.new
         author.save
-        user << author
+        user.author = author
+        user.save
       else
         logger.error { "found an author!" }
         author = user.author