diff --git a/ruby-2.6.0-Update-for-tzdata-2018f.patch b/ruby-2.6.0-Update-for-tzdata-2018f.patch
new file mode 100644
index 0000000..edc58b6
--- /dev/null
+++ b/ruby-2.6.0-Update-for-tzdata-2018f.patch
@@ -0,0 +1,44 @@
+From e71ca6cdcf108e6a2fa47ec9fadefe7554717908 Mon Sep 17 00:00:00 2001
+From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
+Date: Fri, 26 Oct 2018 01:47:09 +0000
+Subject: [PATCH] Update for tzdata-2018f
+
+git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65365 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
+---
+ test/ruby/test_time_tz.rb | 12 +++++++++---
+ 1 file changed, 9 insertions(+), 3 deletions(-)
+
+diff --git a/test/ruby/test_time_tz.rb b/test/ruby/test_time_tz.rb
+index 2da4fd8d9ce4..328fde48fc34 100644
+--- a/test/ruby/test_time_tz.rb
++++ b/test/ruby/test_time_tz.rb
+@@ -86,7 +86,9 @@ def group_by(e, &block)
+   has_lisbon_tz &&= have_tz_offset?("Europe/Lisbon")
+   CORRECT_TOKYO_DST_1951 = with_tz("Asia/Tokyo") {
+     if Time.local(1951, 5, 6, 12, 0, 0).dst? # noon, DST
+-      Time.local(1951, 5, 6, 1, 0, 0).dst?   # DST with fixed tzdata
++      if Time.local(1951, 5, 6, 1, 0, 0).dst? # DST with fixed tzdata
++        Time.local(1951, 9, 8, 23, 0, 0).dst? ? "2018f" : "2018e"
++      end
+     end
+   }
+   CORRECT_KIRITIMATI_SKIP_1994 = with_tz("Pacific/Kiritimati") {
+@@ -347,12 +349,16 @@ def self.gen_zdump_test(data)
+ Asia/Singapore  Thu Dec 31 16:29:59 1981 UTC = Thu Dec 31 23:59:59 1981 SGT isdst=0 gmtoff=27000
+ Asia/Singapore  Thu Dec 31 16:30:00 1981 UTC = Fri Jan  1 00:30:00 1982 SGT isdst=0 gmtoff=28800
+ End
+-  gen_zdump_test CORRECT_TOKYO_DST_1951 ? <<'End' : <<'End'
++  gen_zdump_test CORRECT_TOKYO_DST_1951 ? <<'End' + (CORRECT_TOKYO_DST_1951 < "2018f" ? <<'2018e' : <<'2018f') : <<'End'
+ Asia/Tokyo  Sat May  5 14:59:59 1951 UTC = Sat May  5 23:59:59 1951 JST isdst=0 gmtoff=32400
+ Asia/Tokyo  Sat May  5 15:00:00 1951 UTC = Sun May  6 01:00:00 1951 JDT isdst=1 gmtoff=36000
++End
+ Asia/Tokyo  Sat Sep  8 13:59:59 1951 UTC = Sat Sep  8 23:59:59 1951 JDT isdst=1 gmtoff=36000
+ Asia/Tokyo  Sat Sep  8 14:00:00 1951 UTC = Sat Sep  8 23:00:00 1951 JST isdst=0 gmtoff=32400
+-End
++2018e
++Asia/Tokyo  Sat Sep  8 14:59:59 1951 UTC = Sun Sep  9 00:59:59 1951 JDT isdst=1 gmtoff=36000
++Asia/Tokyo  Sat Sep  8 15:00:00 1951 UTC = Sun Sep  9 00:00:00 1951 JST isdst=0 gmtoff=32400
++2018f
+ Asia/Tokyo  Sat May  5 16:59:59 1951 UTC = Sun May  6 01:59:59 1951 JST isdst=0 gmtoff=32400
+ Asia/Tokyo  Sat May  5 17:00:00 1951 UTC = Sun May  6 03:00:00 1951 JDT isdst=1 gmtoff=36000
+ Asia/Tokyo  Fri Sep  7 15:59:59 1951 UTC = Sat Sep  8 01:59:59 1951 JDT isdst=1 gmtoff=36000
diff --git a/ruby.spec b/ruby.spec
index a4649b1..d2f8501 100644
--- a/ruby.spec
+++ b/ruby.spec
@@ -21,7 +21,7 @@
 %endif
 
 
-%global release 99
+%global release 100
 %{!?release_string:%global release_string %{?development_release:0.}%{release}%{?development_release:.%{development_release}}%{?dist}}
 
 # The RubyGems library has to stay out of Ruby directory tree, since the
@@ -142,6 +142,10 @@ Patch15: ruby-2.6.0-library-options-to-MAINLIBS.patch
 # Do not require C++ compiler.
 # https://github.com/rubygems/rubygems/pull/2367
 Patch16: ruby-2.5.1-Avoid-need-of-C++-compiler-to-pass-the-test-suite.patch
+# Fix Tokyo TZ tests.
+# https://github.com/ruby/ruby/commit/e71ca6cdcf108e6a2fa47ec9fadefe7554717908
+Patch25: ruby-2.6.0-Update-for-tzdata-2018f.patch
+
 # Fix some OpenSSL 1.1.1 test failures.
 # https://github.com/ruby/ruby/commit/1dfc377ae3b174b043d3f0ed36de57b0296b34d0
 Patch19: ruby-2.6.0-net-http-net-ftp-fix-session-resumption-with-TLS-1.3.patch
@@ -530,6 +534,7 @@ rm -rf ext/fiddle/libffi*
 %patch15 -p1
 %patch16 -p1
 %patch19 -p1
+%patch25 -p1
 
 # Provide an example of usage of the tapset:
 cp -a %{SOURCE3} .
@@ -1079,6 +1084,9 @@ make check TESTS="-v $DISABLE_TESTS"
 %{gem_dir}/specifications/xmlrpc-%{xmlrpc_version}.gemspec
 
 %changelog
+* Tue Nov 13 2018 Vít Ondruch <vondruch@redhat.com> - 2.5.3-100
+- Fix Tokyo TZ tests.
+
 * Fri Oct 19 2018 Jun Aruga <jaruga@redhat.com> - 2.5.3-99
 - Update to Ruby 2.5.3.