diff --git a/openbox/extensions.h b/openbox/extensions.h
index 3fbac871..6a488a19 100644
--- a/openbox/extensions.h
+++ b/openbox/extensions.h
@@ -67,6 +67,11 @@ extern gboolean extensions_sync;
 /*! Base for events for the Sync extension */
 extern gint extensions_sync_event_basep;
 
+/*! Does the display have the Composite extension? */
+extern gboolean extensions_comp;
+/*! Base for events for the Composite extension */
+extern gint extensions_comp_event_basep;
+
 void extensions_query_all();
 
 void extensions_xinerama_screens(Rect **areas, guint *nxin);