--- dbus/dbus.scm	2015-07-08 22:17:28.746987420 +0200
+++ dbus-patched/dbus.scm	2015-05-31 20:24:57.469958384 +0200
@@ -275,7 +275,7 @@
 				(if (null? rem-keys)
 					subtree
 					(loop (cdr rem-keys)
-						(let ([pr (assq (car rem-keys) subtree)])
+						(let ([pr (assq (car rem-keys) (or subtree '()))])
 							(and (pair? pr) (cdr pr))))))))
 
 	;; The "tree" version of asset!: drills down into an assq-tree