diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index dcced06d0..49bf8a628 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -606,7 +606,6 @@ Lint/UriEscapeUnescape:
 Lint/UselessAccessModifier:
   Exclude:
     - 'app/models/changeset.rb'
-    - 'app/models/watcher.rb'
     - 'lib/redmine/themes.rb'
 
 Lint/UselessAssignment:
diff --git a/app/models/watcher.rb b/app/models/watcher.rb
index 639e2c988..8ea457060 100644
--- a/app/models/watcher.rb
+++ b/app/models/watcher.rb
@@ -57,8 +57,6 @@ class Watcher < ActiveRecord::Base
     errors.add :user_id, :invalid unless user.nil? || user.active?
   end
 
-  private
-
   def self.prune_single_user(user, options={})
     return unless user.is_a?(User)
     pruned = 0
@@ -79,4 +77,5 @@ class Watcher < ActiveRecord::Base
     end
     pruned
   end
+  private_class_method :prune_single_user
 end