diff --git a/src/compositor-wayland.h b/src/compositor-wayland.h
index 5af5ea7..de69b98 100644
--- a/src/compositor-wayland.h
+++ b/src/compositor-wayland.h
@@ -32,6 +32,8 @@
 extern "C" {
 #endif
 
+#define WESTON_WAYLAND_BACKEND_CONFIG_VERSION 1
+
 struct weston_wayland_backend_output_config {
 	int width;
 	int height;
@@ -41,6 +43,7 @@
 };
 
 struct weston_wayland_backend_config {
+	struct weston_backend_config base;
 	int use_pixman;
 	int sprawl;
 	char *display_name;