diff --git a/.travis.yml b/.travis.yml
index 2d6c734b07..22538cee45 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ rvm:
   - 2.1.10
   - 2.2.5
   - 2.3.1
+  - 2.4.0
   - rbx-2
   - jruby-9.0.5.0
   - jruby-9.1.2.0
diff --git a/Gemfile b/Gemfile
index 95443599d1..532b696b0f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'coveralls', :require => false
+gem 'coveralls', '~> 0.8.17', :require => false
 gem 'pry', :require => false
 
 # JSON gem no longer supports ruby < 2.0.0
diff --git a/spec/money_spec.rb b/spec/money_spec.rb
index 1c3095b913..b7ca736c54 100644
--- a/spec/money_spec.rb
+++ b/spec/money_spec.rb
@@ -191,7 +191,7 @@ def expectation.fractional
     it "stores fractional as an integer regardless of what is passed into the constructor" do
       m = Money.new(100)
       expect(m.fractional).to eq 100
-      expect(m.fractional).to be_a(Fixnum)
+      expect(m.fractional).to be_a(Integer)
     end
 
     context "loading a serialized Money via YAML" do
@@ -351,7 +351,7 @@ def expectation.fractional
 
     it "returns a Fixnum when infinite_precision is not set" do
       money = Money.new(100, "USD")
-      expect(money.round_to_nearest_cash_value).to be_a Fixnum
+      expect(money.round_to_nearest_cash_value).to be_a Integer
     end
 
     it "returns a BigDecimal when infinite_precision is set", :infinite_precision do