diff --git a/org/open_power/Witherspoon/Fault/meson.build b/org/open_power/Witherspoon/Fault/meson.build
index 0669c2e..29f4a3d 100644
--- a/org/open_power/Witherspoon/Fault/meson.build
+++ b/org/open_power/Witherspoon/Fault/meson.build
@@ -3,7 +3,7 @@
     capture: true,
     command: [
         sdbuspp,
-        '-r', meson.source_root(),
+        '-r', meson.project_source_root(),
         'error',
         'exception-header',
         'org.open_power.Witherspoon.Fault',
@@ -19,7 +19,7 @@
     capture: true,
     command: [
         sdbuspp,
-        '-r', meson.source_root(),
+        '-r', meson.project_source_root(),
         'error',
         'exception-cpp',
         'org.open_power.Witherspoon.Fault',