diff --git a/actionpack/lib/action_controller/metal/live.rb b/actionpack/lib/action_controller/metal/live.rb
index 0a77352e57..47a66fc194 100644
--- a/actionpack/lib/action_controller/metal/live.rb
+++ b/actionpack/lib/action_controller/metal/live.rb
@@ -34,6 +34,7 @@ module ActionController
   module Live
     class Buffer < ActionDispatch::Response::Buffer #:nodoc:
       def initialize(response)
+        @error_callback = nil
         super(response, SizedQueue.new(10))
       end
 
diff --git a/activerecord/lib/active_record/railties/databases.rake b/activerecord/lib/active_record/railties/databases.rake
index 93bbeea5a3..48febcbc43 100644
--- a/activerecord/lib/active_record/railties/databases.rake
+++ b/activerecord/lib/active_record/railties/databases.rake
@@ -373,7 +373,7 @@ namespace :railties do
         puts "NOTE: Migration #{migration.basename} from #{name} has been skipped. Migration with the same name already exists."
       end
 
-      on_copy = Proc.new do |name, migration, old_path|
+      on_copy = Proc.new do |name, migration|
         puts "Copied migration #{migration.basename} from #{name}"
       end