diff --git a/util/cairo-script/cairo-script-private.h b/util/cairo-script/cairo-script-private.h
index b1b4aed0e..c60b4185c 100644
--- a/util/cairo-script/cairo-script-private.h
+++ b/util/cairo-script/cairo-script-private.h
@@ -914,7 +914,7 @@ csi_number_get_value (const csi_object_t *obj)
     }
 }
 
-csi_status_t
+csi_private csi_status_t
 _csi_stack_push (csi_t *ctx, csi_stack_t *stack,
 		 const csi_object_t *obj);