1diff --git a/meson.build b/meson.build
2index 28799d8..047e523 100644
3--- a/meson.build
4+++ b/meson.build
5@@ -72,11 +72,15 @@
6 pc_conf = configuration_data()
7 pc_conf.set('prefix', get_option('prefix'))
8 pc_conf.set('exec_prefix', '${prefix}')
9-pc_conf.set('libdir', '${exec_prefix}/' + get_option('libdir'))
10-pc_conf.set('includedir', '${prefix}/' + get_option('includedir'))
11-pc_conf.set('STARTUP_NOTIFICATION_PACKAGE', STARTUP_NOTIFICATION_PACKAGE)
12+pc_conf.set('libdir', '${exec_prefix}' / get_option('libdir'))
13+pc_conf.set('includedir', '${prefix}' / get_option('includedir'))
14+if conf.has('HAVE_' + STARTUP_NOTIFICATION_PACKAGE.to_upper().underscorify())
15+ pc_conf.set('STARTUP_NOTIFICATION_PACKAGE', STARTUP_NOTIFICATION_PACKAGE)
16+endif
17 pc_conf.set('X11_PACKAGE', X11_PACKAGE)
18-pc_conf.set('XRES_PACKAGE', XRES_PACKAGE)
19+if conf.has('HAVE_' + XRES_PACKAGE.to_upper().underscorify())
20+ pc_conf.set('XRES_PACKAGE', XRES_PACKAGE)
21+endif
22 pc_conf.set('VERSION', meson.project_version())
23
24 foreach pc: [PACKAGE_NAME, PACKAGE_NAME + '-uninstalled']