diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 4d2e6518..8c5cd5ad 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -723,9 +723,10 @@ Style/TrailingCommaInLiteral:
     - 'db/migrate/20140701123203_add_events_per_week_to_conference.rb'
     - 'spec/models/conference_spec.rb'
 
-# Offense count: 3
-# Cop supports --auto-correct.
-Style/UnneededInterpolation:
+# Offense count: 2
+# Configuration parameters: EnforcedStyle, SupportedStyles.
+# SupportedStyles: snake_case, normalcase, non_integer
+Style/VariableNumber:
   Exclude:
-    - 'app/helpers/format_helper.rb'
-    - 'spec/controllers/admin/conferences_controller_spec.rb'
+    - 'spec/models/ticket_purchase_spec.rb'
+
diff --git a/app/helpers/format_helper.rb b/app/helpers/format_helper.rb
index 684e3754..2e97a764 100644
--- a/app/helpers/format_helper.rb
+++ b/app/helpers/format_helper.rb
@@ -122,7 +122,7 @@ module FormatHelper
              plural || singular.pluralize
            end
 
-    "#{word}"
+    word.to_s
   end
 
   # Returns black or white deppending on what of them contrast more with the
diff --git a/spec/controllers/admin/conferences_controller_spec.rb b/spec/controllers/admin/conferences_controller_spec.rb
index 009e40ba..d077b917 100644
--- a/spec/controllers/admin/conferences_controller_spec.rb
+++ b/spec/controllers/admin/conferences_controller_spec.rb
@@ -56,8 +56,8 @@ describe Admin::ConferencesController do
           conference.reload
           expect(flash[:error])
               .to eq("Updating conference failed. Short title can't be blank.")
-          expect(conference.title).to eq("#{conference.title}")
-          expect(conference.short_title).to eq("#{conference.short_title}")
+          expect(conference.title).to eq(conference.title.to_s)
+          expect(conference.short_title).to eq(conference.short_title.to_s)
         end
 
         it 're-renders the #show template' do