diff --git a/app/controllers/list_controller.rb b/app/controllers/list_controller.rb
index bf07fdc0282..8339d8b2d3e 100644
--- a/app/controllers/list_controller.rb
+++ b/app/controllers/list_controller.rb
@@ -368,7 +368,7 @@ class ListController < ApplicationController
   def build_topic_list_options
     options = {}
     params[:page] = params[:page].to_i rescue 1
-    params[:tags] = [params[:tag_id]] if params[:tag_id].present? && guardian.can_tag_pms?
+    params[:tags] = [params[:tag_id].parameterize] if params[:tag_id].present? && guardian.can_tag_pms?
 
     TopicQuery.public_valid_options.each do |key|
       options[key] = params[key]