diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index 061ec878c238b..0c64ffdeafe1c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -84,7 +84,6 @@ def initialize(spec)
         @connections         = []
         @checked_out         = []
         @automatic_reconnect = true
-        @visitor             = nil
       end
 
       # Retrieve the connection associated with the current thread, or call