diff --git a/.travis.yml b/.travis.yml
index 3dd8631..eb817f9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,10 +5,12 @@ env:
   matrix:
     - SOLIDUS_BRANCH=v1.3 DB=mysql
     - SOLIDUS_BRANCH=v1.3 DB=postgres
-    - SOLIDUS_BRANCH=master DB=mysql
-    - SOLIDUS_BRANCH=master DB=postgres
+    - SOLIDUS_BRANCH=v1.4 DB=mysql
+    - SOLIDUS_BRANCH=v1.4 DB=postgres
+    - SOLIDUS_BRANCH=v2.0 DB=mysql
+    - SOLIDUS_BRANCH=v2.0 DB=postgres
 script:
   - bundle exec rake test_app
   - bundle exec rspec
 rvm:
-  - 2.1.8
+  - 2.3.3
diff --git a/Gemfile b/Gemfile
index 1b17d76..a3c161b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source "https://rubygems.org"
 
-branch = ENV.fetch('SOLIDUS_BRANCH', 'master')
+branch = ENV.fetch('SOLIDUS_BRANCH', 'v1.4')
 gem "solidus", github: "solidusio/solidus", branch: branch
 gem "solidus_auth_devise", "~> 1.0"
 
diff --git a/solidus_avatax.gemspec b/solidus_avatax.gemspec
index 5f91ce8..f405540 100644
--- a/solidus_avatax.gemspec
+++ b/solidus_avatax.gemspec
@@ -17,7 +17,7 @@ Gem::Specification.new do |s|
   s.require_path = "lib"
   s.requirements << "none"
 
-  s.add_dependency "solidus_core", ">= 1.3.0.alpha", "< 1.4"
+  s.add_dependency "solidus_core", ">= 1.3.0", "< 2.1"
   s.add_dependency "hashie",      "~> 2.l.5"
   s.add_dependency "multi_json"
   s.add_dependency "Avatax_TaxService", "~> 2.0.0"
diff --git a/spec/models/spree/shipping_rate_spec.rb b/spec/models/spree/shipping_rate_spec.rb
index d367ba7..ccb7a69 100644
--- a/spec/models/spree/shipping_rate_spec.rb
+++ b/spec/models/spree/shipping_rate_spec.rb
@@ -1,19 +1,28 @@
 require 'spec_helper'
 
 describe Spree::ShippingRate do
+  let!(:tax_rate) do
+    rate = Spree::TaxRate.first
+    rate.zone.countries << shipment.order.ship_address.country
+    rate
+  end
+
   let(:shipping_rate) do
     shipment.shipping_rates.create!({
-      tax_rate:        Spree::TaxRate.first,
       shipping_method: shipping_method,
       cost:            10.00,
-      selected:        true,
+      selected:        true
     })
   end
 
   let(:shipment) { create(:shipment) }
-  let(:shipping_method) { create(:shipping_method) }
+  let(:shipping_method) { create(:shipping_method, tax_category: tax_rate.tax_category) }
+
+  before do
+    Spree::Config.shipping_rate_taxer_class.new.tax(shipping_rate)
+  end
 
   it 'calculates shipping rate taxes as 0' do
-    expect(shipping_rate.calculate_tax_amount).to eq 0
+    expect(shipping_rate.taxes.first.amount).to eq 0
   end
 end