diff --git a/clutter/cogl/cogl/winsys/cogl-winsys-private.h b/clutter/cogl/cogl/winsys/cogl-winsys-private.h
index 856fc8ded..e09fde99b 100644
--- a/clutter/cogl/cogl/winsys/cogl-winsys-private.h
+++ b/clutter/cogl/cogl/winsys/cogl-winsys-private.h
@@ -144,4 +144,7 @@ typedef struct _CoglWinsysVtable
 
 } CoglWinsysVtable;
 
+gboolean
+_cogl_winsys_has_feature (CoglWinsysFeature feature);
+
 #endif /* __COGL_WINSYS_PRIVATE_H */