diff --git a/.travis.yml b/.travis.yml
index 34bafb0..d10a2ee 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@ cache: bundler
 
 matrix:
   include:
+    - rvm: 2.3
     - rvm: 2.4
     - rvm: 2.5
     - rvm: 2.6
diff --git a/protocol-http.gemspec b/protocol-http.gemspec
index 63320d7..621c72c 100644
--- a/protocol-http.gemspec
+++ b/protocol-http.gemspec
@@ -15,7 +15,7 @@ Gem::Specification.new do |spec|
 		f.match(%r{^(test|spec|features)/})
 	end
 	
-	spec.required_ruby_version = '>= 2.4.0'
+	spec.required_ruby_version = '>= 2.3.0'
 	
 	spec.require_paths = ["lib"]