diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index ff805687b44..e8313fbde47 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -239,7 +239,8 @@ class ApplicationController < ActionController::Base
       find_opts[:active] = true unless opts[:include_inactive]
       User.find_by(find_opts)
     elsif params[:external_id]
-      SingleSignOnRecord.find_by(external_id: params[:external_id]).try(:user)
+      external_id = params[:external_id].gsub(/\.json$/, '')
+      SingleSignOnRecord.find_by(external_id: external_id).try(:user)
     end
     raise Discourse::NotFound.new if user.blank?