diff --git a/demos/meson.build b/demos/meson.build
index 550f90b0de..91eb3c465c 100644
--- a/demos/meson.build
+++ b/demos/meson.build
@@ -3,7 +3,7 @@ demo_profile = get_option('profile')
 
 demo_conf_h = declare_dependency(
   sources: custom_target('demo-header',
-    command: [gen_demo_header, meson.source_root(), demo_profile],
+    command: [gen_demo_header, meson.project_source_root(), demo_profile],
     capture: true,
     output: 'demo_conf.h',
     build_by_default: true,