diff --git a/Gemfile.lock b/Gemfile.lock
index 35681c9b7..f62e1064a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -472,7 +472,7 @@ GEM
       rspec-mocks (~> 3.13)
       rspec-support (~> 3.13)
     rspec-support (3.13.4)
-    rubocop (1.76.1)
+    rubocop (1.76.2)
       json (~> 2.3)
       language_server-protocol (~> 3.17.0.2)
       lint_roller (~> 1.1.0)
@@ -480,7 +480,7 @@ GEM
       parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 2.9.3, < 3.0)
-      rubocop-ast (>= 1.45.0, < 2.0)
+      rubocop-ast (>= 1.45.1, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 4.0)
     rubocop-ast (1.45.1)
@@ -942,7 +942,7 @@ CHECKSUMS
   rspec-mocks (3.13.5) sha256=e4338a6f285ada9fe56f5893f5457783af8194f5d08884d17a87321d5195ea81
   rspec-rails (8.0.1) sha256=0c3700b10ab6d7c648c4cd554023d8c2b5b07e7f01205f7608f0c511cf686505
   rspec-support (3.13.4) sha256=184b1814f6a968102b57df631892c7f1990a91c9a3b9e80ef892a0fc2a71a3f7
-  rubocop (1.76.1) sha256=e15a2d750794cf2157d2de8b1b403dfa71b8dc3957a22ae6043b1bdf21e7e0e7
+  rubocop (1.76.2) sha256=ae44f172ba0bbe3d623c927111798f85a7879bcc88e544d08f51f62c19f45633
   rubocop-ast (1.45.1) sha256=94042e49adc17f187ba037b33f941ba7398fede77cdf4bffafba95190a473a3e
   rubocop-capybara (2.22.1) sha256=ced88caef23efea53f46e098ff352f8fc1068c649606ca75cb74650970f51c0c
   rubocop-factory_bot (2.27.1) sha256=9d744b5916778c1848e5fe6777cc69855bd96548853554ec239ba9961b8573fe
diff --git a/app/helpers/statistics_helper.rb b/app/helpers/statistics_helper.rb
index 1a7e6e8d9..60b68e46e 100644
--- a/app/helpers/statistics_helper.rb
+++ b/app/helpers/statistics_helper.rb
@@ -71,21 +71,21 @@ def exercise_statistics
       {
         key: 'submissions_per_minute',
           name: t('statistics.entries.exercises.submissions_per_minute'),
-          data: (Submission.where(created_at: DateTime.now - 1.hour..).count.to_f / 60).round(2),
+          data: (Submission.where(created_at: (DateTime.now - 1.hour)..).count.to_f / 60).round(2),
           unit: '/min',
           url: statistics_graphs_path,
       },
       {
         key: 'autosaves_per_minute',
           name: t('statistics.entries.exercises.autosaves_per_minute'),
-          data: (Submission.where(created_at: DateTime.now - 1.hour..).where(cause: 'autosave').count.to_f / 60).round(2),
+          data: (Submission.where(created_at: (DateTime.now - 1.hour)..).where(cause: 'autosave').count.to_f / 60).round(2),
           unit: '/min',
       },
       {
         key: 'container_requests_per_minute',
           name: t('statistics.entries.exercises.container_requests_per_minute'),
           # This query is actually quite expensive since we do not have an index on the created_at column.
-          data: (Testrun.where(created_at: DateTime.now - 1.hour..).count.to_f / 60).round(2),
+          data: (Testrun.where(created_at: (DateTime.now - 1.hour)..).count.to_f / 60).round(2),
           unit: '/min',
       },
       {
@@ -118,12 +118,12 @@ def user_activity_live_data
       {
         key: 'active_in_last_hour',
           name: t('statistics.entries.contributors.currently_active'),
-          data: Submission.where(created_at: DateTime.now - 5.minutes..).distinct.select(:contributor_id, :contributor_type).count,
+          data: Submission.where(created_at: (DateTime.now - 5.minutes)..).distinct.select(:contributor_id, :contributor_type).count,
       },
       {
         key: 'submissions_per_minute',
           name: t('statistics.entries.exercises.submissions_per_minute'),
-          data: (Submission.where(created_at: DateTime.now - 1.hour..).count.to_f / 60).round(2),
+          data: (Submission.where(created_at: (DateTime.now - 1.hour)..).count.to_f / 60).round(2),
           unit: '/min',
           axis: 'right',
       },
diff --git a/app/models/event/synchronized_editor.rb b/app/models/event/synchronized_editor.rb
index b0d82b61d..71026f7e5 100644
--- a/app/models/event/synchronized_editor.rb
+++ b/app/models/event/synchronized_editor.rb
@@ -91,12 +91,12 @@ def self.data_attribute(event, delta)
     event.presence if event.present? # TODO: As of now, we are storing the `session_id` most of the times. Intended?
   end
   private_class_method :data_attribute
-end
 
-private
+  private
 
-def lines_not_nil
-  if lines.nil?
-    errors.add(:lines, 'cannot be nil')
+  def lines_not_nil
+    if lines.nil?
+      errors.add(:lines, 'cannot be nil')
+    end
   end
 end