diff --git a/include/xo/object2/DList.hpp b/include/xo/object2/DList.hpp
index 608f82b..a862f18 100644
--- a/include/xo/object2/DList.hpp
+++ b/include/xo/object2/DList.hpp
@@ -65,8 +65,8 @@ namespace xo {
 
             /** assign head **/
             void assign_head(obj<ACollector> gc, obj<AGCObject> h);
-            /** assign rest-pointer **/
-            void assign_rest(DList * r);
+            /** assign rest-pointer. Caller responsible for preserving acyclic property! **/
+            void _assign_rest(DList * r);
 
             /** pretty-printing driver; combine layout+printing **/
             bool pretty(const ppindentinfo & ppii) const;
diff --git a/src/object2/DList.cpp b/src/object2/DList.cpp
index 612ed98..7208bb9 100644
--- a/src/object2/DList.cpp
+++ b/src/object2/DList.cpp
@@ -128,7 +128,7 @@ namespace xo {
         }
 
         void
-        DList::assign_rest(DList * r)
+        DList::_assign_rest(DList * r)
         {
             scope log(XO_DEBUG(true), "need write barrier");