diff --git a/src/include/compositor-mutter.h b/src/include/compositor-mutter.h
index 263485acc..7ab35115f 100644
--- a/src/include/compositor-mutter.h
+++ b/src/include/compositor-mutter.h
@@ -38,7 +38,7 @@
 #define MUTTER_TYPE_COMP_WINDOW       (mutter_window_get_type ())
 #define MUTTER_WINDOW(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), MUTTER_TYPE_COMP_WINDOW, MutterWindow))
 #define MUTTER_WINDOW_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), MUTTER_TYPE_COMP_WINDOW, MutterWindowClass))
-#define IS_MUTTER_WINDOW(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MUTTER_WINDOW_TYPE))
+#define MUTTER_IS_WINDOW(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), MUTTER_TYPE_COMP_WINDOW))
 #define MUTTER_IS_WINDOW_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), MUTTER_TYPE_COMP_WINDOW))
 #define MUTTER_WINDOW_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), MUTTER_TYPE_COMP_WINDOW, MutterWindowClass))