diff --git a/lib/cgi.rb b/lib/cgi.rb
index dda5eb1712..4cd6b3bd8e 100644
--- a/lib/cgi.rb
+++ b/lib/cgi.rb
@@ -288,7 +288,7 @@
 #
 
 class CGI
-  VERSION = "0.3.5"
+  VERSION = "0.3.6"
 end
 
 require 'cgi/core'
diff --git a/lib/cgi/cookie.rb b/lib/cgi/cookie.rb
index 1a9c1a82c1..9498e2f9fa 100644
--- a/lib/cgi/cookie.rb
+++ b/lib/cgi/cookie.rb
@@ -42,7 +42,7 @@ class CGI
 
     TOKEN_RE = %r"\A[[!-~]&&[^()<>@,;:\\\"/?=\[\]{}]]+\z"
     PATH_VALUE_RE = %r"\A[[ -~]&&[^;]]*\z"
-    DOMAIN_VALUE_RE = %r"\A(?<label>(?!-)[-A-Za-z0-9]+(?<!-))(?:\.\g<label>)*\z"
+    DOMAIN_VALUE_RE = %r"\A\.?(?<label>(?!-)[-A-Za-z0-9]+(?<!-))(?:\.\g<label>)*\z"
 
     # Create a new CGI::Cookie object.
     #
diff --git a/test/cgi/test_cgi_cookie.rb b/test/cgi/test_cgi_cookie.rb
index e3ec4bea52..eadae45313 100644
--- a/test/cgi/test_cgi_cookie.rb
+++ b/test/cgi/test_cgi_cookie.rb
@@ -62,18 +62,21 @@ class CGICookieTest < Test::Unit::TestCase
 
   def test_cgi_cookie_new_with_domain
     h = {'name'=>'name1', 'value'=>'value1'}
-    cookie = CGI::Cookie.new('domain'=>'a.example.com', **h)
+    cookie = CGI::Cookie.new(h.merge('domain'=>'a.example.com'))
     assert_equal('a.example.com', cookie.domain)
 
-    cookie = CGI::Cookie.new('domain'=>'1.example.com', **h)
+    cookie = CGI::Cookie.new(h.merge('domain'=>'.example.com'))
+    assert_equal('.example.com', cookie.domain)
+
+    cookie = CGI::Cookie.new(h.merge('domain'=>'1.example.com'))
     assert_equal('1.example.com', cookie.domain, 'enhanced by RFC 1123')
 
     assert_raise(ArgumentError) {
-      CGI::Cookie.new('domain'=>'-a.example.com', **h)
+      CGI::Cookie.new(h.merge('domain'=>'-a.example.com'))
     }
 
     assert_raise(ArgumentError) {
-      CGI::Cookie.new('domain'=>'a-.example.com', **h)
+      CGI::Cookie.new(h.merge('domain'=>'a-.example.com'))
     }
   end
 
diff --git a/version.h b/version.h
index c192428aba..6627f91e2b 100644
--- a/version.h
+++ b/version.h
@@ -11,11 +11,11 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 4
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 188
+#define RUBY_PATCHLEVEL 189
 
-#define RUBY_RELEASE_YEAR 2022
-#define RUBY_RELEASE_MONTH 12
-#define RUBY_RELEASE_DAY 17
+#define RUBY_RELEASE_YEAR 2023
+#define RUBY_RELEASE_MONTH 2
+#define RUBY_RELEASE_DAY 23
 
 #include "ruby/version.h"