diff --git a/app/models/comment.rb b/app/models/comment.rb
index a1d89a33f..1d5c9aa30 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -1,5 +1,6 @@
 class Comment < ActiveRecord::Base
   include Flaggable
+  include HasPublicAuthor
 
   acts_as_paranoid column: :hidden_at
   include ActsAsParanoidAliases
@@ -16,7 +17,6 @@ class Comment < ActiveRecord::Base
 
   belongs_to :commentable, -> { with_hidden }, polymorphic: true, counter_cache: true
   belongs_to :user, -> { with_hidden }
-  belongs_to :public_author, -> { with_public_activity }, class_name: 'User', foreign_key: 'user_id'
 
   before_save :calculate_confidence_score
 
diff --git a/app/models/concerns/has_public_author.rb b/app/models/concerns/has_public_author.rb
new file mode 100644
index 000000000..a1af255c5
--- /dev/null
+++ b/app/models/concerns/has_public_author.rb
@@ -0,0 +1,5 @@
+module HasPublicAuthor
+  def public_author
+    self.author.public_activity? ? self.author : nil
+  end
+end
diff --git a/app/models/debate.rb b/app/models/debate.rb
index 13cff5b3f..5e7491b83 100644
--- a/app/models/debate.rb
+++ b/app/models/debate.rb
@@ -7,13 +7,13 @@ class Debate < ActiveRecord::Base
   include Sanitizable
   include Searchable
   include Filterable
+  include HasPublicAuthor
 
   acts_as_votable
   acts_as_paranoid column: :hidden_at
   include ActsAsParanoidAliases
 
   belongs_to :author, -> { with_hidden }, class_name: 'User', foreign_key: 'author_id'
-  belongs_to :public_author, -> { with_public_activity }, class_name: 'User', foreign_key: 'author_id'
   belongs_to :geozone
   has_many :comments, as: :commentable
 
diff --git a/app/models/proposal.rb b/app/models/proposal.rb
index 64cadbb24..ad51436b0 100644
--- a/app/models/proposal.rb
+++ b/app/models/proposal.rb
@@ -6,6 +6,7 @@ class Proposal < ActiveRecord::Base
   include Sanitizable
   include Searchable
   include Filterable
+  include HasPublicAuthor
 
   acts_as_votable
   acts_as_paranoid column: :hidden_at
@@ -14,7 +15,6 @@ class Proposal < ActiveRecord::Base
   RETIRE_OPTIONS = %w(duplicated started unfeasible done other)
 
   belongs_to :author, -> { with_hidden }, class_name: 'User', foreign_key: 'author_id'
-  belongs_to :public_author, -> { with_public_activity }, class_name: 'User', foreign_key: 'author_id'
   belongs_to :geozone
   has_many :comments, as: :commentable
   has_many :proposal_notifications