diff --git a/app/models/bid.rb b/app/models/bid.rb
index 038c45cd5..02569ade1 100644
--- a/app/models/bid.rb
+++ b/app/models/bid.rb
@@ -42,9 +42,9 @@ class Bid < ActiveRecord::Base
   validates :author_id, presence: true
   validates :deadline, presence: true, format: {:with => /^[\d]{4}[-][\d]{1,2}[-][\d]{1,2}$/}
   validates :name, length: {maximum: NAME_LENGTH_LIMIT}
-  validates :budget,
-            format: {with : /^(\d+)$|^(\d+).([0-9]{2})|^(\d+).([0-9]{1})$/, if:  Proc.new { |p| p.reward_type == 1 }},
-            format: {with:  /^(\d+)$|^(\d+).([0-9]{1})$/, if: Proc.new { |p| p.reward_type == 3 }}
+  validates :budget, format: { with: ->(p) { if p.reward_type == 1 then /^(\d+)$|^(\d+).([0-9]{2})|^(\d+).([0-9]{1})$/
+                                             elsif p.reward_type == 3 then /^(\d+)$|^(\d+).([0-9]{1})$/ end } }
+
   validate :validate_user
   validate :validate_reward_type
   after_create :act_as_activity