diff --git a/ext/sdbm/sdbm.gemspec b/ext/sdbm/sdbm.gemspec
index 54ff21f1f6..3627d2800b 100644
--- a/ext/sdbm/sdbm.gemspec
+++ b/ext/sdbm/sdbm.gemspec
@@ -1,15 +1,16 @@
 # frozen_string_literal: true
+
 Gem::Specification.new do |s|
   s.name = "sdbm"
-  s.version = '0.0.1'
-  s.date = '2017-02-28'
+  s.version = '1.0.0'
+  s.date = '2017-12-11'
   s.summary = "Provides a simple file-based key-value store with String keys and values."
   s.description = "Provides a simple file-based key-value store with String keys and values."
 
   s.require_path = %w{lib}
   s.files = %w{ext/sdbm/_sdbm.c ext/sdbm/depend ext/sdbm/extconf.rb ext/sdbm/init.c ext/sdbm/sdbm.h}
   s.extensions = ["ext/sdbm/extconf.rb"]
-  s.required_ruby_version = ">= 2.5.0dev"
+  s.required_ruby_version = ">= 2.3.0"
 
   s.authors = ["Yukihiro Matsumoto"]
   s.email = ["matz@ruby-lang.org"]