--- a/configure.ac
+++ b/configure.ac
@@ -20,7 +20,7 @@
 PKG_CHECK_MODULES(XCB, xcb xcb-ewmh)
 
 PKG_CHECK_MODULES(DBUS_GLIB, dbus-glib-1 >= 0.80)
-SESSION_BUS_SERVICES_DIR=`$PKG_CONFIG --variable=session_bus_services_dir dbus-1`
+SESSION_BUS_SERVICES_DIR=$prefix/share/dbus-1/services
 AC_SUBST([SESSION_BUS_SERVICES_DIR])
 
 AC_ARG_WITH(
@@ -32,35 +32,35 @@
 AS_IF(
     [test "x$panel" = xgnome2],
         [PKG_CHECK_MODULES(LIBPANEL, libpanelapplet-3.0 >= 2.32.0)]
-        LIBPANEL_APPLET_DIR=`$PKG_CONFIG --variable=prefix libpanelapplet-3.0`/share/gnome-panel/applets
-        PLUGIN_DIR=`$PKG_CONFIG --variable=prefix libpanelapplet-3.0`/libexec
+        LIBPANEL_APPLET_DIR=$prefix/share/gnome-panel/applets
+        PLUGIN_DIR=$prefix/libexec
         [AC_DEFINE(PANEL_GNOME, 1, [panel type])]
         [AC_DEFINE(PANEL_GNOME2, 1, [panel type])]
         ,
     [test "x$panel" = xgnome3],
         [PKG_CHECK_MODULES(LIBPANEL, libpanelapplet-4.0 >= 3.0.0)]
-        LIBPANEL_APPLET_DIR=`$PKG_CONFIG --variable=libpanel_applet_dir libpanelapplet-4.0`
-        PLUGIN_DIR=`$PKG_CONFIG --variable=prefix libpanelapplet-4.0`/libexec
+        LIBPANEL_APPLET_DIR=`$PKG_CONFIG --define-variable=prefix=$prefix --variable=libpanel_applet_dir libpanelapplet-4.0`
+        PLUGIN_DIR=$prefix/libexec
         [AC_DEFINE(PANEL_GNOME, 1, [panel type])]
         [AC_DEFINE(PANEL_GNOME3, 1, [panel type])]
         ,
     [test "x$panel" = xgnomeflashback],
         [PKG_CHECK_MODULES(LIBPANEL, libpanel-applet >= 3.0.0)]
-        LIBPANEL_APPLET_DIR=`$PKG_CONFIG --variable=libpanel_applet_dir libpanel-applet`
-        PLUGIN_DIR=`$PKG_CONFIG --variable=prefix libpanel-applet`/libexec
+        LIBPANEL_APPLET_DIR=`$PKG_CONFIG --define-variable=prefix=$prefix --variable=libpanel_applet_dir libpanel-applet`
+        PLUGIN_DIR=$prefix/libexec
         [AC_DEFINE(PANEL_GNOME, 1, [panel type])]
         [AC_DEFINE(PANEL_GNOMEFLASHBACK, 1, [panel type])]
         ,
     [test "x$panel" = xmate],
         [PKG_CHECK_MODULES(LIBPANEL, libmatepanelapplet-4.0 >= 1.4.0)]
-        LIBPANEL_APPLET_DIR=`$PKG_CONFIG --variable=prefix libmatepanelapplet-4.0`/share/mate-panel/applets
-        PLUGIN_DIR=`$PKG_CONFIG --variable=prefix libmatepanelapplet-4.0`/libexec
+        LIBPANEL_APPLET_DIR=$prefix/share/mate-panel/applets
+        PLUGIN_DIR=$prefix/libexec
         [AC_DEFINE(PANEL_MATE, 1, [panel type])]
         ,
     [test "x$panel" = xxfce4],
         [PKG_CHECK_MODULES(LIBPANEL, libxfce4panel-1.0 >= 4.6.0)]
-        LIBPANEL_APPLET_DIR=`$PKG_CONFIG --variable=prefix libxfce4panel-1.0`/share/xfce4/panel-plugins
-        PLUGIN_DIR=`$PKG_CONFIG --variable=libdir libxfce4panel-1.0`/xfce4/panel/plugins
+        LIBPANEL_APPLET_DIR=$prefix/share/xfce4/panel-plugins
+        PLUGIN_DIR=`$PKG_CONFIG --define-variable=prefix=$prefix --variable=libdir libxfce4panel-1.0`/xfce4/panel/plugins
         [AC_DEFINE(PANEL_XFCE4, 1, [panel type])]
         ,
     [AC_MSG_ERROR([Unknown panel type, use gnome2, gnome3, gnomeflashback, mate or xfce4])]