diff --git a/govuk_app_config.gemspec b/govuk_app_config.gemspec
index 8a9a73d..d522758 100644
--- a/govuk_app_config.gemspec
+++ b/govuk_app_config.gemspec
@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
   spec.homepage      = "https://github.com/alphagov/govuk_app_config"
   spec.license       = "MIT"
 
-  spec.required_ruby_version = ">= 3.0"
+  spec.required_ruby_version = ">= 3.1.4"
 
   spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
   spec.bindir        = "exe"