diff --git a/.travis.yml b/.travis.yml
index 45a71d83c..a91d70cf5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,7 @@ addons:
   postgresql: 9.4
 
 rvm:
+  - 2.3.4
   - 2.4.1
 
 services:
diff --git a/Gemfile b/Gemfile
index 5d75c11ea..0165219d3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 source 'https://rubygems.org'
-ruby '2.4.1'
+ruby '>= 2.3.0', '< 2.5.0'
 
 gem 'pkg-config'