diff --git a/.travis.yml b/.travis.yml
index 2ac51bbf..05ec2da6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,4 +14,5 @@ matrix:
   allow_failures:
     - rvm: ruby-head
     - env: "RAILS_VERSION=master"
+    - env: "RAILS_VERSION=4.0"
 
diff --git a/Gemfile b/Gemfile
index 565aad0e..25b466eb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 # Specify your gem's dependencies in active_model_serializers.gemspec
 gemspec
 
-gem "minitest", "~>5.1"
+gem "minitest"
 
 version = ENV["RAILS_VERSION"] || "4.1"