diff --git a/dbus.spec b/dbus.spec
index 5f4e683..a4b6149 100644
--- a/dbus.spec
+++ b/dbus.spec
@@ -81,7 +81,7 @@ other supporting documentation such as the introspect dtd file.
 %package devel
 Summary: Development files for D-BUS
 Group: Development/Libraries
-Requires: %{name} = %{epoch}:%{version}-%{release}
+Requires: %{name}%{?_isa} = %{epoch}:%{version}-%{release}
 
 %description devel
 This package contains libraries and header files needed for
@@ -90,15 +90,18 @@ developing software that uses D-BUS.
 %package x11
 Summary: X11-requiring add-ons for D-BUS
 Group: Development/Libraries
-Requires: %{name} = %{epoch}:%{version}-%{release}
+Requires: %{name}%{?_isa} = %{epoch}:%{version}-%{release}
+Requires: xorg-x11-xinit
 
 %description x11
 D-BUS contains some tools that require Xlib to be installed, those are
 in this separate package so server systems need not install X.
 
+
 %prep
 %setup -q -n %{name}-%{version}
 
+
 %build
 # Avoid rpath.
 if test -f autogen.sh; then env NOCONFIGURE=1 ./autogen.sh; else autoreconf --verbose --force --install; fi
@@ -223,12 +226,14 @@ ln -s %{_pkgdocdir} %{buildroot}%{_datadir}/gtk-doc/html/dbus
 %{_libdir}/pkgconfig/dbus-1.pc
 %{_includedir}/*
 
+
 %changelog
 * Wed Dec 03 2014 David King <amigadave@amigadave.com> - 1:1.8.12-2
 - Drop bindir patch, and update to comply with UsrMove
 - Correct license description for multiple licenses
 - Use macroized systemd scriptlets (#850083)
 - Add some more documentation from the upstream tarball
+- Tighten subpackage dependencies by using %%{?_isa}
 
 * Wed Nov 26 2014 David King <amigadave@amigadave.com> - 1:1.8.12-1
 - Update to 1.8.12 (#1168438)