diff --git a/app/controllers/users_for_private_messages_controller.rb b/app/controllers/users_for_private_messages_controller.rb
index bbd5682a1..1caf52a6c 100644
--- a/app/controllers/users_for_private_messages_controller.rb
+++ b/app/controllers/users_for_private_messages_controller.rb
@@ -2,7 +2,7 @@ class UsersForPrivateMessagesController < ApplicationController
   before_action :require_login, :check_auth
 
   def index
-    users = User.active.where.not(id: current_user.id)
+    users = User.active.where.not(id: current_user.id).where(laboratory_id: current_laboratory.id)
 
     keyword = params[:keyword].to_s.strip
     if keyword.blank?