diff --git a/.rubocop.yml b/.rubocop.yml
index ca819d9d..bf158032 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -92,6 +92,10 @@ Style/TrailingBlankLines:
 Style/TrailingWhitespace:
   Enabled: true
 
+#This cop checks for numeric comparisons that can be replaced by a predicate method.
+Style/ZeroLengthPredicate:
+  Enabled: true
+
 #################### Metrics ###############################
 
 # Avoid deep blocks nesting
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 47e50eb9..a0487443 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -680,8 +680,3 @@ Style/UnneededInterpolation:
 Style/WordArray:
   EnforcedStyle: percent
   MinSize: 3
-
-# Offense count: 1
-Style/ZeroLengthPredicate:
-  Exclude:
-    - 'app/models/conference.rb'
diff --git a/app/models/conference.rb b/app/models/conference.rb
index 5b868ca9..1d549ec7 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -464,7 +464,7 @@ class Conference < ActiveRecord::Base
     result = Conference.where('start_date > ?', Time.now).
         select('id, short_title, color, start_date')
 
-    if result.length == 0
+    if result.empty?
       result = Conference.
           select('id, short_title, color, start_date').limit(2).
           order(start_date: :desc)