diff --git a/syobocalite.gemspec b/syobocalite.gemspec
index 3b91f69..9dd9ea6 100644
--- a/syobocalite.gemspec
+++ b/syobocalite.gemspec
@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.homepage      = "https://github.com/sue445/syobocalite"
   spec.license       = "MIT"
 
-  spec.required_ruby_version = ">= 2.3.0"
+  spec.required_ruby_version = ">= 2.5.0"
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage
@@ -31,8 +31,6 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.required_ruby_version = ">= 2.5.0"
-
   spec.add_dependency "activesupport"
   spec.add_dependency "multi_xml"