--- a/configure.ac
+++ b/configure.ac
@@ -34,10 +34,11 @@
 PKG_CHECK_MODULES(GTK2,[gtk+-2.0 >= $GTK2_VERSION])
 PKG_CHECK_MODULES(GTKMM2, [gtkmm-2.4 >= $GTKMM2_VERSION])
 PKG_CHECK_MODULES(GTHREAD2, [gthread-2.0 >= $GTHREAD2_VERSION])
+PKG_CHECK_MODULES(X11, x11)
 
 
-NITROGEN_LIBS="$GLIB2_LIBS $GTK2_LIBS $GTKMM2_LIBS $GTHREAD2_LIBS"
-NITROGEN_CFLAGS="$GLIB2_CFLAGS $GTK2_CFLAGS $GTKMM2_CFLAGS $GTHREAD2_CFLAGS"
+NITROGEN_LIBS="$GLIB2_LIBS $GTK2_LIBS $GTKMM2_LIBS $GTHREAD2_LIBS $X11_LIBS"
+NITROGEN_CFLAGS="$GLIB2_CFLAGS $GTK2_CFLAGS $GTKMM2_CFLAGS $GTHREAD2_CFLAGS $X11_CFLAGS"
 
 dnl do some autotools picen to get inotify
 AC_ARG_ENABLE(inotify, [  --disable-inotify       disable support for inotify watching of dirs (default: enabled)], [enable_inotify=$enableval],[enable_inotify=yes])