diff --git a/lib/lepus/rails/railtie.rb b/lib/lepus/rails/railtie.rb
index 2a024fa..9de60f0 100644
--- a/lib/lepus/rails/railtie.rb
+++ b/lib/lepus/rails/railtie.rb
@@ -9,7 +9,7 @@ class Railtie < ::Rails::Railtie
     initializer "lepus.app_executor", before: :run_prepare_callbacks do |app|
       config.lepus.app_executor ||= app.executor
       if ::Rails.respond_to?(:error) && config.lepus.on_thread_error.nil?
-        config.lepus.on_thread_error = ->(exception) { Rails.error.report(exception, handled: false) }
+        config.lepus.on_thread_error = ->(exception) { ::Rails.error.report(exception, handled: false) }
       elsif config.lepus.on_thread_error.nil?
         config.lepus.on_thread_error = ->(exception) { Lepus.logger.error(exception) }
       end
diff --git a/lib/lepus/supervisor.rb b/lib/lepus/supervisor.rb
index 930e921..3272687 100644
--- a/lib/lepus/supervisor.rb
+++ b/lib/lepus/supervisor.rb
@@ -55,7 +55,7 @@ def boot
           begin
             require "rails"
             require_relative "rails"
-            require File.expand_path("config/environment", Dir.pwd)
+            Kernel.require File.expand_path("config/environment", Dir.pwd)
           rescue LoadError
             # Rails not found
           end