diff --git a/nbdkit.spec b/nbdkit.spec
index 5c841f4..e17bf77 100644
--- a/nbdkit.spec
+++ b/nbdkit.spec
@@ -20,8 +20,8 @@
 %global verify_tarball_signature 1
 
 Name:           nbdkit
-Version:        1.3.4
-Release:        4%{?dist}
+Version:        1.4.0
+Release:        1%{?dist}
 Summary:        NBD server
 
 License:        BSD
@@ -64,7 +64,7 @@ BuildRequires:  e2fsprogs-devel
 BuildRequires:  bash-completion
 BuildRequires:  perl-devel
 BuildRequires:  perl(ExtUtils::Embed)
-BuildRequires:  python2-devel
+BuildRequires:  python2-devel, python-unversioned-command
 %if 0%{?have_python3}
 BuildRequires:  python3-devel
 %endif
@@ -74,8 +74,9 @@ BuildRequires:  python3-devel
 BuildRequires:  ocaml >= 4.02.2
 %endif
 BuildRequires:  ruby-devel
+BuildRequires:  tcl-devel
 %if 0%{verify_tarball_signature}
-BuildRequires: gnupg2
+BuildRequires:  gnupg2
 %endif
 
 # Only for running the test suite:
@@ -344,6 +345,17 @@ Requires:       %{name}%{?_isa} = %{version}-%{release}
 This package is a tar archive plugin for %{name}.
 
 
+%package plugin-tcl
+Summary:        Tcl plugin for %{name}
+License:        BSD
+
+Requires:       %{name}%{?_isa} = %{version}-%{release}
+
+
+%description plugin-tcl
+This package lets you write Tcl plugins for %{name}.
+
+
 %package plugin-xz
 Summary:        XZ file serving plugin for %{name}
 License:        BSD
@@ -464,7 +476,7 @@ make %{?_smp_mflags}
 %if 0%{?have_python3}
 pushd python3
 export PYTHON=%{_bindir}/python3
-%configure --disable-static --disable-perl --disable-ocaml --disable-ruby
+%configure --disable-static --disable-perl --disable-ocaml --disable-ruby --disable-tcl
 # Verify that it picked the correct version of Python
 # to avoid RHBZ#1404631 happening again silently.
 grep '^PYTHON_VERSION = 3' Makefile
@@ -661,6 +673,13 @@ popd
 %{_mandir}/man1/nbdkit-tar-plugin.1*
 
 
+%files plugin-tcl
+%doc README
+%license LICENSE
+%{_libdir}/%{name}/plugins/nbdkit-tcl-plugin.so
+%{_mandir}/man3/nbdkit-tcl-plugin.3*
+
+
 %files plugin-xz
 %doc README
 %license LICENSE
@@ -700,6 +719,7 @@ popd
 %doc plugins/perl/example.pl
 %doc plugins/python/example.py
 %doc plugins/ruby/example.rb
+%doc plugins/tcl/example.tcl
 %{_includedir}/nbdkit-common.h
 %{_includedir}/nbdkit-filter.h
 %{_includedir}/nbdkit-plugin.h
@@ -715,6 +735,11 @@ popd
 
 
 %changelog
+* Fri Jul  6 2018 Richard W.M. Jones <rjones@redhat.com> - 1.4.0-1
+- New upstream version 1.4.0.
+- Add nbdkit-plugin-tcl subpackage.
+- +BR python-unversioned-command
+
 * Tue Jul 03 2018 Petr Pisar <ppisar@redhat.com> - 1.3.4-4
 - Perl 5.28 rebuild
 
diff --git a/sources b/sources
index f9d1725..eda5482 100644
--- a/sources
+++ b/sources
@@ -1,2 +1,2 @@
-SHA512 (nbdkit-1.3.4.tar.gz) = ba9a91511b79f50a190b8857ca8fd37f9d663d41ff0defb6c67b9e1c2511d17e3aa5a8b5643b633698a3f22f984e276ab9cf3c098a79a84634d3166891147b75
-SHA512 (nbdkit-1.3.4.tar.gz.sig) = 26146aafc31f068ed9759e0e74d4317dc5ee4be6653c04dd6f7dbcd80808831782debeffffc065b570b9fa9a53125f811ccf47ccfca6d5a84653d0b356f56aae
+SHA512 (nbdkit-1.4.0.tar.gz) = c9503f074ef767c0d75d9869d2374763494b13a9ce27a0b9d48fe83b6975bd4e81662d967fd20e2212a05621c7899cc40c4056985bb82c1efb9b50fb94b2d168
+SHA512 (nbdkit-1.4.0.tar.gz.sig) = bcd2a7d6e2fa45d93d3b2eec9ab15c52ed1ef1a3aaa5dd7beb1ca3ad52d9621826457ef1513c6166d6173282da42a04b73a1384d32ce0c66398ecac90d39b98a