diff --git a/varnish-5.2.1-python3.patch b/varnish-5.2.1-python3.patch
new file mode 100644
index 0000000..f83385a
--- /dev/null
+++ b/varnish-5.2.1-python3.patch
@@ -0,0 +1,66 @@
+From 17c92e43fda114bf5341e51d752e882238b8fe8c Mon Sep 17 00:00:00 2001
+From: Nils Goroll <nils.goroll@uplex.de>
+Date: Thu, 5 Oct 2017 13:39:23 +0200
+Subject: [PATCH] hack up vsctool to work with python 2 and 3
+
+StringIO does not exist any more in python3, yet requiring 2.7 would
+not pave the path forward, so try to be compatible with both.
+
+Works for me on Python 2.7.9 and Python 3.4
+
+I would appreciate if someone more fluent in serpentinous programming
+language reviewed and/or rewrote this.
+---
+ lib/libvcc/vsctool.py | 24 ++++++++++++++++++++----
+ 1 file changed, 20 insertions(+), 4 deletions(-)
+
+diff --git a/lib/libvcc/vsctool.py b/lib/libvcc/vsctool.py
+index 854968e3b..829c6e518 100644
+--- a/lib/libvcc/vsctool.py
++++ b/lib/libvcc/vsctool.py
+@@ -37,7 +37,10 @@
+ import json
+ import sys
+ import gzip
+-import StringIO
++try:
++    import StringIO
++except ImportError:
++    import io
+ import collections
+ import struct
+ 
+@@ -54,9 +57,22 @@
+ 	"format":	[ "integer", FORMATS],
+ }
+ 
++# http://python3porting.com/problems.html#bytes-strings-and-unicode
++if sys.version_info < (3,):
++    def b(x):
++        return x
++else:
++    import codecs
++    def b(x):
++        return codecs.latin_1_encode(x)[0]
++
+ def gzip_str(s):
+-	out = StringIO.StringIO()
+-	gzip.GzipFile(fileobj=out, mode="w").write(s)
++	try:
++		out = StringIO.StringIO()
++	except NameError:
++		out = io.BytesIO()
++
++	gzip.GzipFile(fileobj=out, mode="w").write(b(s))
+ 	out.seek(4)
+ 	out.write(struct.pack("<L", 0x12bfd58))
+ 	return out.getvalue()
+@@ -285,7 +301,7 @@ class rst_vsc(directive):
+ 	def __init__(self, s):
+ 		super(rst_vsc, self).__init__(s)
+ 
+-		for i,v in PARAMS.iteritems():
++		for i,v in PARAMS.items():
+ 			if v is not True:
+ 				self.do_default(i, v[0], v[1])
+ 
diff --git a/varnish.spec b/varnish.spec
index b474509..c144851 100644
--- a/varnish.spec
+++ b/varnish.spec
@@ -14,10 +14,17 @@
 %define commit1 5b976190ce9e0720f1eee6e9eaccd8a15eaa498d
 %global shortcommit1 %(c=%{commit1}; echo ${c:0:7})
 
+%bcond_without python2
+%bcond_with python3
+
+%if %{with python2} == %{with python3}
+%error Pick exactly one Python version
+%endif
+
 Summary: High-performance HTTP accelerator
 Name: varnish
 Version: 5.2.1
-Release: 4%{?v_rc}%{?dist}.1
+Release: 5%{?v_rc}%{?dist}
 License: BSD
 Group: System Environment/Daemons
 URL: http://www.varnish-cache.org/
@@ -26,14 +33,18 @@ Source1: https://github.com/varnishcache/pkg-varnish-cache/archive/%{commit1}.ta
 Patch1:  varnish-5.1.1.fix_ld_library_path_in_doc_build.patch
 Patch4:  varnish-4.0.3_fix_varnish4_selinux.el6.patch
 Patch6:  varnish-4.1.0.fix_find-provides.patch
+Patch8:  varnish-5.2.1-python3.patch
 Patch9:  varnish-5.1.1.fix_python_version.patch
 Patch10: vsv00002_test.patch
 
-
+%if %{with python3}
+BuildRequires: python3-sphinx, python3-docutils
+%else
 %if 0%{?rhel} >= 6
 BuildRequires: python-sphinx
 %endif
 BuildRequires: python-docutils
+%endif
 BuildRequires: ncurses-devel
 BuildRequires: groff
 BuildRequires: pcre-devel
@@ -104,7 +115,11 @@ Summary: Development files for %{name}-libs
 Group: Development/Libraries
 BuildRequires: ncurses-devel
 Requires: varnish-libs = %{version}-%{release}
+%if %{with python3}
+Requires: python3
+%else
 Requires: python
+%endif
 Provides: varnish-libs-devel = %{version}-%{release}
 Obsoletes: varnish-libs-devel
 
@@ -139,6 +154,7 @@ ln -s pkg-varnish-cache-%{commit1}/debian debian
 %patch9 -p0
 %endif
 %patch6 -p0
+%patch8 -p1
 %patch10 -p0
 
 %build
@@ -193,7 +209,11 @@ make %{?_smp_mflags} V=1
 sed -i 's,User=varnishlog,User=varnish,g;' redhat/varnishncsa.service
 
 # Explicit python, please
+%if %{with python2}
 sed -i 's/env python/python2/g;' lib/libvcc/vmodtool.py
+%else
+sed -i 's/env python/python3/g;' lib/libvcc/vmodtool.py
+%endif
 
 # Clean up the sphinx documentation
 rm -rf doc/sphinx/build/html/_sources
@@ -402,6 +422,9 @@ fi
 %endif
 
 %changelog
+* Wed Mar 28 2018 Joe Orton <jorton@redhat.com> - 5.2.1-5
+- add conditional build support for Python 3
+
 * Fri Feb 09 2018 Fedora Release Engineering <releng@fedoraproject.org> - 5.2.1-4.1
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_28_Mass_Rebuild