diff --git a/app/models/person.rb b/app/models/person.rb
index 1761e71..0e943fa 100644
--- a/app/models/person.rb
+++ b/app/models/person.rb
@@ -33,6 +33,7 @@ class Person < Profile
   end
 
   validates_presence_of :user_id
+  validates_uniqueness_of :user_id
 
   def initialize(*args)
     super(*args)
--
libgit2 0.21.2