diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index <HASH>..<HASH> 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -1,5 +1,4 @@
 require 'active_record/type'
-require 'active_support/core_ext/benchmark'
 require 'active_record/connection_adapters/determine_if_preparable_visitor'
 require 'active_record/connection_adapters/schema_cache'
 require 'active_record/connection_adapters/sql_type_metadata'
Remove unused require

`require 'active_support/core_ext/benchmark'` was added by 4ecdf<I>.
But currently unused anymore.