diff --git a/app/controllers/readings_controller.rb b/app/controllers/readings_controller.rb
index 3a08dee..de4259c 100644
--- a/app/controllers/readings_controller.rb
+++ b/app/controllers/readings_controller.rb
@@ -54,7 +54,7 @@ class ReadingsController < ActionController::API
                      r.tap do |r|
                        r.name = params[:controller_id]
                        r.serial_number = params[:serial_number]
-                       r.public_keys.find_or_create_by(content: request.headers[:'X-Public-Key'])
+                       r.public_keys.find_or_create_by(content: params[:public_key])
                        r.save
                      end
                    end