diff --git a/CHANGELOG.md b/CHANGELOG.md
index 814cf6e68..bb3db7540 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 - Improved automated testing
 - Added an information notice about the processing time of deleting an administrator
 - Fix a bug: unable to run rake db:migrate on first install
+- Fix a bug: unable to create or edit a coupon of type 'percentage'
 
 ## v2.4.6 2016 Novembre 30
 
diff --git a/app/validators/coupon_discount_validator.rb b/app/validators/coupon_discount_validator.rb
index 35b81b0f6..072ae089f 100644
--- a/app/validators/coupon_discount_validator.rb
+++ b/app/validators/coupon_discount_validator.rb
@@ -1,7 +1,7 @@
 class CouponDiscountValidator < ActiveModel::Validator
   def validate(record)
     if !record.percent_off.nil?
-      unless [0..100].include? record.percent_off
+      unless (0..100).include? record.percent_off
         record.errors[:percent_off] << 'Percentage must be included between 0 and 100'
       end
     elsif !record.amount_off.nil?