diff --git a/core/app/models/spree/price.rb b/core/app/models/spree/price.rb
index defe76c780..59cf304d51 100644
--- a/core/app/models/spree/price.rb
+++ b/core/app/models/spree/price.rb
@@ -13,7 +13,7 @@ class Price < Spree::Base
     delegate :tax_rates, to: :variant
 
     validate :check_price
-    validates :amount, allow_nil: true, numericality: {
+    validates :amount, numericality: {
       greater_than_or_equal_to: 0,
       less_than_or_equal_to: MAXIMUM_AMOUNT
     }
diff --git a/core/db/migrate/20210312061050_change_column_null_on_prices.rb b/core/db/migrate/20210312061050_change_column_null_on_prices.rb
new file mode 100644
index 0000000000..19c88ce3a2
--- /dev/null
+++ b/core/db/migrate/20210312061050_change_column_null_on_prices.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class ChangeColumnNullOnPrices < ActiveRecord::Migration[5.2]
+  def change
+    change_column_null(:spree_prices, :amount, false)
+  end
+end
diff --git a/core/lib/tasks/migrations/delete_prices_with_nil_amount.rake b/core/lib/tasks/migrations/delete_prices_with_nil_amount.rake
new file mode 100644
index 0000000000..96cbaafda3
--- /dev/null
+++ b/core/lib/tasks/migrations/delete_prices_with_nil_amount.rake
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+namespace :solidus do
+  namespace :migrations do
+    namespace :delete_prices_with_nil_amount do
+      task up: :environment do
+        print "Deleting prices wich amount attribute is nil ... "
+        Spree::Price.where(amount: nil).delete_all
+        puts "Success"
+      end
+    end
+  end
+end
diff --git a/core/lib/tasks/upgrade.rake b/core/lib/tasks/upgrade.rake
index d57aba14e4..cb10b9cf31 100644
--- a/core/lib/tasks/upgrade.rake
+++ b/core/lib/tasks/upgrade.rake
@@ -9,5 +9,12 @@ namespace :solidus do
       ] do
       puts "Your Solidus install is ready for Solidus 2.11"
     end
+
+    desc "Upgrade Solidus to version 3.0"
+    task three_point_zero: [
+        'solidus:migrations:delete_prices_with_nil_amount:up',
+      ] do
+      puts "Your Solidus install is ready for Solidus 3.0"
+    end
   end
 end
diff --git a/core/spec/lib/tasks/migrations/delete_prices_with_nil_amount_spec.rb b/core/spec/lib/tasks/migrations/delete_prices_with_nil_amount_spec.rb
new file mode 100644
index 0000000000..331fab94b8
--- /dev/null
+++ b/core/spec/lib/tasks/migrations/delete_prices_with_nil_amount_spec.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+path = Spree::Core::Engine.root.join('lib/tasks/migrations/delete_prices_with_nil_amount.rake')
+
+RSpec.describe 'solidus:migrations:delete_prices_with_nil_amount' do
+  describe 'up' do
+    include_context(
+      'rake',
+      task_path: path,
+      task_name: 'solidus:migrations:delete_prices_with_nil_amount:up'
+    )
+
+    it 'removes all prices which amount column is NULL' do
+      price = create(:price)
+      expect(Spree::Price).to receive(:where).with(amount: nil).and_return(Spree::Price.where(id: price))
+
+      task.invoke
+
+      expect { price.reload }.to raise_error(ActiveRecord::RecordNotFound)
+    end
+  end
+end
diff --git a/core/spec/models/spree/price_spec.rb b/core/spec/models/spree/price_spec.rb
index f9e76f2612..c285a28c13 100644
--- a/core/spec/models/spree/price_spec.rb
+++ b/core/spec/models/spree/price_spec.rb
@@ -16,7 +16,7 @@
 
     context 'when the amount is nil' do
       let(:amount) { nil }
-      it { is_expected.to be_valid }
+      it { is_expected.not_to be_valid }
     end
 
     context 'when the amount is less than 0' do