diff --git a/.travis.yml b/.travis.yml
index 45a71d83c457c3f9c99da9c541fbd54487da59dc..a91d70cf5889c9867471e365f9ebbafb09e857f1 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 5d75c11ea7209daa227baf9a88323a7906d436b1..0165219d3779a2f470c627d665f785f023897a48 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'