diff --git a/.gitignore b/.gitignore
index 15b69a4..cd55c38 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /List-MoreUtils-XS-0.418.tar.gz
+/List-MoreUtils-XS-0.421.tar.gz
diff --git a/List-MoreUtils-XS-0.418-unbundle.patch b/List-MoreUtils-XS-0.421-unbundle.patch
similarity index 83%
rename from List-MoreUtils-XS-0.418-unbundle.patch
rename to List-MoreUtils-XS-0.421-unbundle.patch
index dcec9da..fc355af 100644
--- a/List-MoreUtils-XS-0.418-unbundle.patch
+++ b/List-MoreUtils-XS-0.421-unbundle.patch
@@ -26,12 +26,12 @@
  );
  my %BUNDLE_CONFIGURE_DEPS = (
 -    'inc::latest'      => '0.500',
-     'Config::AutoConf' => '0.308',
+     'Config::AutoConf' => '0.315',
  );
  my %CONFIGURE_DEPS = (
---- t/lib/LMU/Test/Functions.pm
-+++ t/lib/LMU/Test/Functions.pm
-@@ -16,7 +16,6 @@ eval "use Scalar::Util qw(); \$have_scal
+--- t/lib/Test/LMU.pm
++++ t/lib/Test/LMU.pm
+@@ -16,7 +16,6 @@ my $CLASS = __PACKAGE__;
  eval "use Storable qw();";
  $@ or Storable->import(qw(freeze));
  __PACKAGE__->can("freeze") or eval <<'EOFR';
diff --git a/perl-List-MoreUtils-XS.spec b/perl-List-MoreUtils-XS.spec
index 8ac3642..c011f00 100644
--- a/perl-List-MoreUtils-XS.spec
+++ b/perl-List-MoreUtils-XS.spec
@@ -1,6 +1,6 @@
 Name:		perl-List-MoreUtils-XS
-Version:	0.418
-Release:	6%{?dist}
+Version:	0.421
+Release:	1%{?dist}
 Summary:	Provide compiled List::MoreUtils functions
 # Code from List-MoreUtils < 0.417 is GPL+ or Artistic
 # Anything after that is ASL 2.0
@@ -9,26 +9,29 @@ Summary:	Provide compiled List::MoreUtils functions
 License:	(GPL+ or Artistic) and ASL 2.0
 URL:		http://search.cpan.org/dist/List-MoreUtils-XS/
 Source0:	http://search.cpan.org/CPAN/authors/id/R/RE/REHSACK/List-MoreUtils-XS-%{version}.tar.gz
-Patch0:		List-MoreUtils-XS-0.418-unbundle.patch
+Patch0:		List-MoreUtils-XS-0.421-unbundle.patch
 # Module Build
 BuildRequires:	coreutils
 BuildRequires:	findutils
 BuildRequires:	gcc
 BuildRequires:	make
-BuildRequires:	perl-interpreter >= 4:5.16.0
 BuildRequires:	perl-devel
 BuildRequires:	perl-generators
-BuildRequires:	perl(base)
+BuildRequires:	perl-interpreter
 BuildRequires:	perl(Capture::Tiny)
-BuildRequires:	perl(Config::AutoConf) >= 0.308
+BuildRequires:	perl(Config::AutoConf) >= 0.315
 BuildRequires:	perl(ExtUtils::CBuilder)
 # Module Runtime
-BuildRequires:	perl(List::MoreUtils) >= 0.418
+BuildRequires:	perl(base)
+BuildRequires:	perl(Exporter)
 BuildRequires:	perl(strict)
 BuildRequires:	perl(vars)
 BuildRequires:	perl(warnings)
-BuildRequires:	perl(XSLoader)
+BuildRequires:	perl(XSLoader) >= 0.22
 # Test Suite
+BuildRequires:	perl(JSON::PP)
+BuildRequires:	perl(List::Util)
+BuildRequires:	perl(Math::Trig)
 BuildRequires:	perl(overload)
 BuildRequires:	perl(Storable)
 BuildRequires:	perl(Test::Builder::Module)
@@ -37,7 +40,6 @@ BuildRequires:	perl(Test::More) >= 0.96
 BuildRequires:	perl(Tie::Array)
 # Runtime
 Requires:	perl(:MODULE_COMPAT_%(eval "`perl -V:version`"; echo $version))
-Requires:	perl(List::MoreUtils) >= 0.418
 
 # Don't "provide" private Perl libs
 %{?perl_default_filter}
@@ -70,12 +72,30 @@ make test
 
 %files
 %license ARTISTIC-1.0 GPL-1 LICENSE
-%doc Changes README.md
+%doc Changes MAINTAINER.md README.md
 %{perl_vendorarch}/auto/List/
 %{perl_vendorarch}/List/
 %{_mandir}/man3/List::MoreUtils::XS.3*
 
 %changelog
+* Tue Aug 15 2017 Paul Howarth <paul@city-fan.org> - 0.421-1
+- Update to 0.421
+  - Fix a lot of potential memory leaks when callbacks throw exceptions
+  - Add some new functions: qsort, binsert, bremove, listcmp, arrayify
+    (CPAN RT#17230), samples (CPAN RT#77562), minmaxstr (CPAN RT#106401),
+    lower_bound, upper_bound, equal_range, frequencies, occurances, mode
+    (CPAN RT#91991), zip6 (CPAN RT#42921), reduce_0, reduce_1, reduce_u
+  - Improve tests
+  - Make List::MoreUtils::XS independent from List::MoreUtils
+    Note that List::MoreUtils::XS doesn't guarantee API stability: this
+    feature is only provided through List::MoreUtils as frontend
+  - Improve configure toolchain to use Config::AutoConf 0.315
+  - Speed up some inner loops by hinting the expected result
+  - Fix mind screwed up issue in upper_bound and reduce elements visited in
+    equal_range
+  - Correct license in META (CPAN RT#122702)
+  - Fix issues with -DPERL_IMPLICIT_SYS on Windows with Strawberry-Perl
+
 * Thu Aug 03 2017 Fedora Release Engineering <releng@fedoraproject.org> - 0.418-6
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_27_Binutils_Mass_Rebuild
 
diff --git a/sources b/sources
index 680539b..fc57ae3 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (List-MoreUtils-XS-0.418.tar.gz) = 1f6b9adfe641afe45ee3bb9d6df8f81d20916cff860c4955200026302da82799939d309dd2412af10ad1874e4e0528a63e8852e543a667942f1c582cb522b4b1
+SHA512 (List-MoreUtils-XS-0.421.tar.gz) = 46312cf5c8d65041d0c88027d653d0ff96ca2908d905eb88d64435de6d7e28687ca912f47a8f878e002b0b72f5af0fcde0a7e7846be43351027ae4f86676332d