diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index 12265d94f958b..e06c991e0fbe9 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -813,7 +813,7 @@ def size
       # to <tt>collection.size.zero?</tt>. If the collection has not been loaded,
       # it is equivalent to <tt>!collection.exists?</tt>. If the collection has
       # not already been loaded and you are going to fetch the records anyway it
-      # is better to check <tt>collection.length.zero?</tt>.
+      # is better to check <tt>collection.load.empty?</tt>.
       #
       #   class Person < ActiveRecord::Base
       #     has_many :pets