diff --git a/activesupport/lib/active_support/buffered_logger.rb b/activesupport/lib/active_support/buffered_logger.rb
index 71308eed67..775f9928e6 100644
--- a/activesupport/lib/active_support/buffered_logger.rb
+++ b/activesupport/lib/active_support/buffered_logger.rb
@@ -1,5 +1,6 @@
 require 'thread'
 require 'logger'
+require 'active_support/core_ext/logger'
 require 'active_support/core_ext/class/attribute_accessors'
 require 'active_support/deprecation'
 require 'fileutils'