diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 5b4a02137..2f7eb1c78 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -802,10 +802,6 @@ Security/IoMethods:
     - 'test/functional/mail_handler_controller_test.rb'
     - 'test/unit/mail_handler_test.rb'
 
-Security/Open:
-  Exclude:
-    - 'app/models/version.rb'
-
 # This cop supports unsafe autocorrection (--autocorrect-all).
 Security/YAMLLoad:
   Exclude:
diff --git a/app/models/version.rb b/app/models/version.rb
index b1327f068..eed2e22d7 100644
--- a/app/models/version.rb
+++ b/app/models/version.rb
@@ -106,7 +106,7 @@ module FixedIssuesExtension
     @issues_progress[open] ||= begin
       progress = 0
       if count > 0
-        done = open(open).sum do |c|
+        done = self.open(open).sum do |c|
           estimated = c.total_estimated_hours.to_f
           estimated = estimated_average unless estimated > 0.0
           ratio = c.closed? ? 100 : (c.done_ratio || 0)