diff --git a/meson.build b/meson.build
index 8ab2f77..68f4503 100644
--- a/meson.build
+++ b/meson.build
@@ -42,6 +42,12 @@
      get_option('authorities-list-name')
 )
 
+if not get_option('allow-expired').disabled()
+  config_data.set('allow_expired', 'true')
+else
+  config_data.set('allow_expired', 'false')
+endif
+
 configure_file(
     input: 'config.h.in',
     output: 'config.h',