diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index e36a6a4f0..883976311 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -2,12 +2,8 @@ class Admin::UsersController < Admin::BaseController
   load_and_authorize_resource
 
   def index
-    if params[:search]
-      s = params[:search]
-      @users = User.where("username ILIKE ? OR email ILIKE ? OR document_number ILIKE ?", "%#{s}%", "%#{s}%", "%#{s}%").page(params[:page])
-    else
-      @users = @users.page(params[:page])
-    end
+    @users = User.by_username_email_or_document_number(params[:search]) if params[:search]
+    @users = @users.page(params[:page])
     respond_to do |format|
       format.html
       format.js
diff --git a/app/models/user.rb b/app/models/user.rb
index 527ae3abc..25f0d8c37 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -64,6 +64,10 @@ class User < ActiveRecord::Base
   scope :public_for_api, -> { all }
   scope :by_comments,    ->(query, topics_ids) { joins(:comments).where(query, topics_ids).uniq }
   scope :by_authors,     ->(author_ids) { where("users.id IN (?)", author_ids) }
+  scope :by_username_email_or_document_number, ->(search_string) do
+    string = "%#{search_string}%"
+    where("username ILIKE ? OR email ILIKE ? OR document_number ILIKE ?", string, string, string)
+  end
 
   before_validation :clean_document_number